this is an interesting question i’ve had banging around in my mind since well before Reddit’s implosion (and Discord’s enshittification), but which seems really worth asking now.
you can’t blame Reddit and Discord or their imitators entirely for these going out of style, but they’ve sure put the dagger in a lot of remaining ones, and i kind of wonder if they’re just in an irreversible and terminal decline a la USENET. i can only name two or three i even consider checking anymore, and i’m not sure how sustainable any of those are long-term.
Like you said, with so many people online now keeping communities healthy is this precarious balancing act of keeping it just hard enough to find so that it doesn’t get flooded yet still discoverable enough for some new members to find it.
definitely feels like if you wanted to make this work these days you’d be relying 100% on word of mouth. search engines seem basically useless (and perhaps irreversibly so) for finding small, independent communities