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.
i think how people talk about the vibe overall might be (a lot of forums were rancid in hindsight), but the community aspect you mention here was very real. it’s just a lot harder to get to know people even on a place like this, which was less the case with older forums–and especially ones on the smaller side. with those it was (and still is where they exist) very possible to get to know people in a meaningful sense and consider them friends. most of my online friends are people i know through forums that way, actually!