I think that's the future, for geeks and nerds anyway. Small private forums, where you can actually have real discussions without getting drowned in memes and downvotes.
For the masses, I think the cement is pretty much dry at this point. You might see a TikTok replace an Instagram once per decade, or something like that. But whatever people migrate to will probably be extremely similar to the thing they migrated from. It's just what the casual masses want.
I find these terrible for any kind of information discovery. I hate that so many communities are using them as an alternative to a subreddit or focused forum. Hell most "modern" forum software is horrific as well.
Chats are a horrible place for evergreen knowledge. Forums are pretty good though.
It’s only a slight difference but a big one.
As a Reddit alternative, Ruqqus has the UI and responsiveness down pretty good. However, it branded itself as anti-reddit, and attracted a lot of right-wing people as a result. However, their platform is open source, so IMO, it's only a matter of time before someone steps up to the task.