In my experience, the content can make a huge difference. For example videogames like Factorio or Minecraft almost feel like writing software to me. Because they require creativity and problem solving skills, just like coding.
There are also huge differences in YouTube videos. Some are very informative and thought-provoking. Watching them does certainly not make me "dumber".
I also don't understand why you distinguish between Books (fiction) and Books (nonfiction). Isn't that the same medium but with different content?