I'm currently working on an early-stage startup on this space, and we're specifically trying to solve the discoverability problem while keeping the group chats themselves small and private (or at least private enough). Do you think you could see yourself using something like this?
How you end up in these groups is you either get invited by real life friends or you hang around in a big public group for a while, make friends with people who will then invite you to these smaller groups.
Because users have to be invited rather than just finding the group on a search page, the users are of higher quality and share similar interests.
Myself personally, probably not. I mentioned I tend a bit towards grumpy isolationism, that's very much the truth.
I will participate in communities I stumble on, but can't see myself seeking them out.
That being said, if I were seeking a community, I could definitely see myself using a service like that.
I've found HN to be much better for discussion in general (recognizing that this is not the case for everyone), and have participated in IRC rooms and whatnot where if I spent more time I could probably consider the people there friends, while still retaining individualism.
I tend towards grumpy isolationism however, so I may not be a good standard.