I agree with the sentence you quote from Vervaeke ("[myths] are symbolic stories of perennial patterns that are always with us") but mostly-disagree with "myths ... encapsulate some eternal and valuable truths" (your paraphrase).

As an example, let's take the story of Cain and Abel. IMO, it is a symbolic story containing many perennial patterns:

• When one person is praised, the not-praised will often envy them
• Brothers often envy each other
• Those who envy often act against those they envy
• Those who envy, or do violence, often lie about it ("Am I my brother's keeper?")
• Those who have done endured strange events sometimes have a "mark of Cain" that leads others to stay at a distance from them and leave them alone

I suspect this story and its patterns (especially back when there were few stories passed down and held in common) helped many to make conscious sense of what they were seeing, and to share their sense with those around them ("it's like Cain and Abel"). But this help (if I'm right about it) would've been similar to the way words in English (or other natural languages) help people make conscious sense of what they're seeing, and communicate that sense -- myths helped people have short codes for common patterns, helped make those patterns available for including in hypotheses and discussions. But myths didn't  much help with making accurate predictions in one shot, the way "eternal and valuable truths" might suggest.

(You can say that useful words are accurate predictions, a la "cluster structures in thingspace". And this is technically true, which is why I am only mostly disagreeing with "myths encapsulate some eternal and valuable truths". But a good word helps differently than a good natural law or something does).

To take a contemporary myth local to our subculture: I think HPMOR is a symbolic story that helps make many useful patterns available to conscious thought/discussion. But it's richer as a place to see motifs in action (e.g. 

) than as a source of directly stateable truths.

• The Good Samaritan is a biblical parable about valuing proximity more highly than ingroup status when extending compassion.
• Reynard the Fox was a popular character in medieval England whose flanderised personality trait was using cunning to defeat the might of the bear, the lion, and other anthropomorphised animals.
• Toy Story is a parable about jealousy, rage, and accepting how the passage of time and shifting social dynamics might change your role in society.

Not sure if that's what you're looking for, but Aesop's Fables do a good job conveying non-trivial wisdom e.g., the fox and the grapes 

Joseph Heinrich has several examples along with a proposed theory to explain them in his two most recent books Weirdest People in the World, and The Secret of our Success . Roughly the theory goes that certain things cannot be rediscovered by trial and error quickly enough. For example, many indigenous people have myths that guide how they prepare food, for example casava. The South American stories tell them how to prepare it, based on their myths, and those instructions ensure they clear out the cyanide before eating it. In Africa where it was transplanted the locals have no such myths, and the toxin builds up very slowly over decades. By the time it kills you, you are unlikely to point the blame at the food everyone has been eating apparently safely. As a result the deaths in Africa are Many times higher than those is South America because of differences in preparation. Many stories and myths work like this.

He also describes several that exist to help people get past major cognitive biases. Like using the randomness of divination to avoid falling into a pattern of hunting (recency bias among others) which prey could learn and adapt to. There is always a myth that goes with the practice.

Astral Codex Ten has a good recent article on this.

While the debate is ongoing, the Cinderella effect may be an example. That is whether the percentage chance of abuse by a non blood relative is higher than by a blood relative. Arguments seem to revolve around lower absolute rates by step parents vs higher percentage rates; and issues with data reliability.

Prophet Elijah was a loyal servant of god and instead of dying he got an uber directly to heaven on a badass burning chariot.

Eternal truth: That’s where all those burning chariots are going. 

I often think about iconic comic book characters as essentially today's version of these kind of mythical stories, which cut across people's disagreements about religion. The story of Spider Man has been retold many times but generally contains a classic arc:

• Peter finds himself unexpectedly with a lot of power all of a sudden.
• Peter has an opportunity to use that power to do the right thing at effectively low cost to himself, and chooses not to for selfishness/laziness reasons.
• His choice not to do right has unforeseeable negative consequences both for society and for him personally.
• He then dedicates himself to saving people/fighting crime/etc.
• In many versions of the story, he pays a lot of personal costs for the time and energy he spends helping others, but he still does it.
• In many versions, at some point he gets burned out or panicked that it feels like his power to do good becomes an obligation he can't escape, and he feels distraught by all the people he cannot help.
• In many versions, he eventually (through some dramatic event) comes to terms with his inability to save everyone, and learns that what he can accomplish is still valuable and good, even if he can't save everyone.

I think its essentially an aspirational model of what it means to be a good person living a balanced life as you come of age and gain authority, power, and responsibility over others. And I do think that people absorb these truths from the story.

I gave a good faith attempt to think of good examples of myths that encapsulate eternal and valuable truths. But unfortunately, instead of good examples, many counterexamples immediately burst into my mind. Many myths depict essentially misogynistic views of women: Eve, Pandora, Circe, Helen, the Sirens. Many myths show how dangerous it is to anger the gods, sometimes for almost nothing—such as being noisy in the Mesopotamian flood myth, or through hubris: Babel, Icarus, and many others. Or they suggest that to appease the gods it is acceptable to sacrifice animals or people, including one's own child: Isaac's sacrifice (stopped at the last second), Iphigenia's sacrifice...

Myths might hold wisdom within the narrow context of a specific culture, but eternal truths? I'm dubious.

I think we see this often in myths that stay with us as powerful allegories because they exemplify a trope or pattern that we may want to express. For example, the myth of Orpheus and Eurydice could exemplify how excessive greed or inability to control your urges can lead to losing everything. Orpheus quite literally fails the "marshmallow test". A similar thing happens in the story of Eros and Psyche, though in this case through her own perseverance Psyche manages to eventually win back what she lost. David vs Goliath is a story about how moral fortitude, courage and wits can triumph in the face of naked brutish violence. The tale of Hua Mulan is a story about the conflict between duty to the family and duty to the law, and how one navigates that (so is the story of Antigone who buries her traitorous brother and gets executed for it).

The thing is also, these are patterns, not universal truths - you'll sometimes find myths expressing opposing patterns because both can hold in the appropriate circumstances. And some myths simply express values that we do not acknowledge any more as worth uplifting. Abraham and Isaac is about blind obedience and faith unto God. The Tower of Babel is about how if you try to build or do something too ambitious you'll get smacked down, and you should just know your place.

We have a lot more stories that have become established with this "mythic" power today, if anything. David and Goliath is also Frodo and Sauron or Luke Skywalker and the Death Star. If you think about the ties between power and responsibility your mind likely evokes Spider-Man's famous motto. No parable about vicious ambition eating itself and leading to a disastrous fall is better known today than the Tale of Walter White, He Who Broke Bad. And the old stories aren't dead. We know more about other cultures than we used to. We eat that shit up, if anything. We have games and shows and comics about the Greek-Roman gods and their myths, and about the Norse, and about the classic Biblical stories... Are these myths weakened by the fact we don't literally believe in their truth any more? But well, look at for how long Christian Europe still hung onto classical pagan myths as a source of metaphor. You only need walk through a frescoed 18th century palace, go visit a museum, read the Divine Comedy to see medieval and early modern artists expressing themselves with the language of Greek gods and heroes. Did they literally believe those to be true? Obviously not, they were good Christians who would never do that. But they believed them to be meaningful and powerful and thus sort of story-true instead of true-true. I think we're doing perfectly fine on that department, and if we're not it's because of limits and constraints to artistic expression which have more to do with its commercial model than any spiritual impoverishment. Requiring people to literally believe every single myth they reference is factual would require them to be naive idiots. And we still have our supposedly true-true myths that still are in some sense myths - meaning they double as powerful stories imbued with meaning. We have stories about the creation of the world by the Big Bang, about the rise and fall of the powerful Dinosaurs, about the rise of one clever ape who managed to spread across the world and become Man, about all sorts of kings and heroes and empires and their wars and struggles. I'd argue the mythical cycle built around World War 2 is in some sense the creation myth of the modern liberal world. These myths of course don't quite look the same way that the Iliad and Odyssey did - but then, does anything look the same as 3000 years ago?

Perhaps instead of thinking of myths as eternal Truths, its more useful to think of them as heuristics, or easy ways to capture and communicate complex ideas.  Tech for thinking complex thoughts.  Humans rarely have the capacity to think abstractly, so we mostly reason by metaphor to something concrete. 

From this perspective, stories and metaphors give shape to the kinds of thoughts people can think.

I think of Chinese Cheng Yu, the 4 character idioms that refer to stories that have morals or lessons, as being the most compressed form of this. Most cultures, from ancient Greece to rural America, have some form of this. 

When s someone references a Less Wrong phrase that conveys a complex idea via a metaphor, like Cupstacking,  the Map is not the Territory, they are doing the same thing. To some extent, one of the projects of Less Wrong is to replace and expand a vernacular.

On the other hand, recently Americans have been fed a glut of superhero, Western,  and epic fantasy stories that have a single clear Good guy and Bad guy, and a straight forward arc of the person winning (usually though violence) being the Good guy, or at least Our guy. There is a struggle for power, honor, respect, justice, safety, the girl (or her memory), and all that is right. Whoever opposes the Protagonist/POV character is the bad guy by default. 

This story has very little to do with universal truths, but it does shape thinking, especially when so often repeated. 

Vampires.

They are night dwelling monsters who look like humans (predatory people tend to sneak around at night) 

They trick you and drain your blood (you can be convinced to do what they want, giving them your life force or even dying) 

They can make others into a vampire (can recruit people into their evil group)

(My favorite) They need to be invited into your home. A piece wisdom for the overly agreeable! 

Maybe the vampire story originated from a story about a violent gang member tricking innocent people and killing them, recruiting for his gang etc. But over the years, storytellers enhance the story, making it an incredibly potent version of itself. 

Perhaps, too, we internalise the story, and when we meet someone who's a little off, the image of a vampire will pop into our heads.