I think you are missing out on a key second half to this story, which would make your motivational take at the end ("uh.. feel good about yourself for trying or something?") a lot stronger:

When you go to a ski resort, or a gym, or etc, it's not JUST that you only see the people who ski, work out, etc, while not seeing the 90% who don't do that activity.  You see people WEIGHTED by the AMOUNT OF TIME they spend doing that activity, which skews heavily towards the most intense practitioners.

For example, suppose your local gym has 21 patrons:
- 7 have lapsed in their actual workout habit; they never show up to the gym even though they keep getting auto-charged the monthly fee because they've forgotten to cancel their membership.
- 7 manage to keep up a healthy but not outstanding workout habit -- they each manage to do a one-hour workout once a week
- 7 are total gym bros who get in a one-hour workout every single day, stacking those gainz

On a typical day, who visits the gym?
- zero of the lapsed members
- on average, just one of the once-a-week members (7 * 1/7 = 1)
- all seven of the hardcore gym rats

So, it's not just that you never see the lapsed members (or the people who never signed up in the first place).  It's also that you get an extremely skewed view of who "goes to the gym" -- visiting the gym and looking around makes it seem like the clientele  is 87.5% hardcore gym rats, when the true proportion is actually just 50%.  (Albeit that 87.5% of the "total time spent in the gym" is spent by gym rats.)

You even mention this in some of your anecdotes, like "most of the other riders have been out 90 days just this season".

For me, this fact is heartening.  For something like a gym or a ski resort (or the blog posts in your feed), comparing yourself to the people you see around you is actually setting a really high bar, since the people you see around you are weighted by the time they spend doing the activity (and/or by the number of posts they write).  A gentler, more intermediate basis of comparison is to all the people who do "go skiing", but don't go every day -- the huge shadow mass of people who ski a couple times a year, whose population is probably way higher than the "I have a cabin next to the resort and buy the season pass every winter" contingent, but who are in the minority every day on the mountain.

I find it difficult to take pride in beating people at something they don't care about and haven't tried to be good at

Dan Luu's classic essay 95%-ile isn't that good nicely complements yours.

Reaching 95%-ile isn't very impressive because it's not that hard to do. I think this is one of my most ridiculable ideas. It doesn't help that, when stated nakedly, that sounds elitist. But I think it's just the opposite: most people can become (relatively) good at most things.

Note that when I say 95%-ile, I mean 95%-ile among people who participate, not all people (for many activities, just doing it at all makes you 99%-ile or above across all people). I'm also not referring to 95%-ile among people who practice regularly. The "one weird trick" is that, for a lot of activities, being something like 10%-ile among people who practice can make you something like 90%-ile or 99%-ile among people who participate.

This post is going to refer to specifics since the discussions I've seen about this are all in the abstract, which turns them into Rorschach tests. For example, Scott Adams has a widely cited post claiming that it's better to be a generalist than a specialist because, to become "extraordinary", you have to either be "the best" at one thing or 75%-ile at two things. If that were strictly true, it would surely be better to be a generalist, but that's of course exaggeration and it's possible to get a lot of value out of a specialized skill without being "the best"; since the precise claim, as written, is obviously silly and the rest of the post is vague handwaving, discussions will inevitably devolve into people stating their prior beliefs and basically ignoring the content of the post.

Personally, in every activity I've participated in where it's possible to get a rough percentile ranking, people who are 95%-ile constantly make mistakes that seem like they should be easy to observe and correct. "Real world" activities typically can't be reduced to a percentile rating, but achieving what appears to be a similar level of proficiency seems similarly easy.

We'll start by looking at Overwatch (a video game) in detail because it's an activity I'm familiar with where it's easy to get ranking information and observe what's happening, and then we'll look at some "real world" examples where we can observe the same phenomena, although we won't be able to get ranking information for real world examples¹. ...

I'm coming at this from the point of view of implied opportunities.  I want to improve in my hobbies, and I'd like to maximize the enjoyment I get out of doing them.  The path of least resistance is likely to expose me to a peer group who intimidate me, and from whom learning will be difficult or impossible due to a large skill gap.

Peers in the same performance range are going to be more difficult to coordinate with, because they are only engaging in the hobby as often as I am, which is far less than the high performers I would be trying to avoid.  Most enthusiast groups I've encountered are generally populated by the high performers as well.  It feels like there is an underserved market for bringing together the mid-tier hobbyists who aren't engaged by a beginner group and haven't reached a level to be comfortable around the advanced practitioners who dominate typical clubs.

My own experience points towards outsized rewards from finding an very enthusiastic beginner to partner with.  They provide the schedule flexibility, and you provide what mentorship you can.  You know that they will surpass you in time, but you can build confidence and grow with them until they get to a point that you're not in their peer group any longer.

So, Where is Everyone?

At Planet Fitness? Ha.

But to be serious, if I understand correctly, Planet Fitness tries to make itself a place where the 97% feel comfortable enough to go to the gym. A place where the median person isn't pushing 6 plates on the bench press and 14 on the leg press. It'd be cool if that sort of thing happened in more domains.

I think a lot of people who talk about being n-th percentile in some domain implicitly only include the set of people who participate in the activity at all. That's a bit less clear-cut than "everyone alive", but makes more sense to talk about and compare against imo.