I think it's the same thing with most social apps though. Small discord servers allow you to build up groups of online friends, but if you just go into the specific game ones you're going to end up with a mix of good and bad.
Overall it's just an issue of popularity bringing out the worst in people.
I don't really agree, it's the issue of aggregating everything relevant to a subject, which makes the popularity relevant.
BBS were not aggregated by subject. They're aggregated by the BBS itself. For a given game, there may be 10 BBS. That's how it was before. You'd go to the BBS with the community style you prefer. You have a choice.
Now, you're just stuck with one subreddit/Discord server/etc., which just reduces the quality of it all. And given the poor organizational ability of those services, it becomes entirely driven by a mix of popularity and posting speed.
[also no skin in the game for the BBS owner, as there is no BBS owner. No BBS competition]
It's the same with most "social apps", yes, because discussion shouldn't occur on "social apps", it should occur on private moderated spaces.
If you're into anything gaming related, good luck. I've been on some subreddits of popular games and it's basically just like the rest of Reddit. In particular, Reddit's system just doesn't work well when there's a lot of users. And the drawback is that these subreddits tend to dominate the space so people do not make private, limited gaming BBS boards as much anymore.