[ineptech]

I think you're right and prescient, and I'm sad that it's happening now that I'm old. In my 20s I had hours and hours and hours to burn on forums and BBSes and muds and such, and found my way in to some cool communities. I loved participating in them, the in-jokes, and even some of the drama involved.

But those places are all moribund now, and the modern closed equivalent of those communities on decentralized services that I would love to be a part of are, by definition, closed to me because I've got a demanding job and kids and stuff. I might have enough time to participate in such a community, but nowhere near enough to try out a bunch and find one where I'd fit in. And an invite is unlikely, because if I were a part of a great closed community I'd be very cautious about bringing in outsiders.

But for younger people, with more time to join a group, participate for a while, realize it's not the right fit, try another one, etc, until they find a tribe they mesh with, I think what you're describing is spot on - meaningful online interactions will be driven out of the public eye, and traditional social media will grow to resemble Linkedin even more than it already does.

[ineptech]

...and fake edit to add, part of the great thing about the 90s and early 2000s online communities is how unfiltered they were. A forum devoted to politics is a terrible place to discuss politics; the battle lines are already drawn and there's nothing to do but fight. But if you join a forum devoted to sailboats because you like sailboats, and hang around long enough to make friends, and end up discussing politics, a) you will hear opinions you've never been exposed to before, and b) since they're coming from people you already somewhat know and like, it's less likely to devolve into a flamewar.