I'm guessing it has to do with our early-adopter status still. Gotta remember, we're still the scrappy little underdog that only the weirdos know about. We are all weirdos, you, me, everyone else. Being here is sufficient to make that true. Over time that'll change, but for now we're just too unknown still.
So, what you have here is a lot of idealists that disapprove of reddit, a lot of people that got banned from reddit and can't go back, and a lot of tech bros and excited young people in general.
You can probably see how these different demographics can kinda come together to create what we see around us here, while a lot of the more "normie" content is still mostly back where we came from. (for us reddit refugees anyway)
That said, you can find a small handful of support group communities for things like alcoholics, and the food and cat subs tend to be fairly active and not so much of a constant clickbait downer. The various AskWhatever subs aren't bad either, though activity is still very light.
We're still in the very early stages though, a phase that'll probably last another year or two. Give us time, we don't even have our software at full functionality yet.