I'm still a regular user of RPG.net and a new user at the Gauntlet forums. There was a time I stopped using them -- mostly while G+ was peaking -- but they fill that hole again.
I was a moderator for Legendfire: Writing Forum for several years, and it was a great writing forum of decent folks, but the last two years of its existence was just a mess. We closed shop in 2017 because it was too much for my friend (who owned the site) and myself to keep it alive what with all the stuff that was happening that year. Plus the moderating team had internal fights that turned too problematic, and there wasn't a lot of reliable folks to find for moderators. So, for those exiled writers from that forum, I created a discord server, and most of the good peeps migrated there to talk about writing and game narratives.
About 10 years ago I was a regular on a small local forum. I met many good friends there, most have simply vanished but the few that I remained in contact with have been with me since, despite the forum's demise 8 years ago.
Presently, one of my best friends happens to be a person I met there, and another person from that place happens to be my significant other (for six years and counting.)
Thinking about it, it's insane just how much some obscure small forum I joined on a whim back then impacted my life.
Well, the Gauntlet forums that opened like three days before these here XD
But it's all a weird throwback to late 90s/early 00s, tbh. All the more so with the same typical silly and unnecessary and childish drama that's cropped up, already.
What I notice most is how ways of communication have changed. I think what I miss in forums are reactions; a like or <3 is not quite enough but I also am more sensitive to a posting a reply with some semblance of content and not just a "this. so much this" or something.
But I'm glad there are now places to have persistent and public discussions/longer takes; I never really got into being active on G+ and while Discords/Slacks are good and important, I'm glad this aspect is being covered.
And to be clear: I think it's a good thing to have multiple such places and not just one central location. Ideally they have strong overlaps. I strongly hope we take an open minded approach to each other, learn of each other and not fall into us vs them camps.
The big question I have is how the values of those more private/closed communities that these have sprung out of get to be propagated and lived in these public spaces. I'm excited for this, here, especially because who has taken the lead for this space that is tied so closely to creators' ways to distribute their stuff.
It's a bit embarrassing to admit, but I'm a regular over on the Something Awful forums (yes, they continue to exist). I know that community has a bit of a reputation online, and it's largely deserved. The tradgames sub-forum generally tends to be chill with a more progressive edge to it, so it's definitely not as bad as some parts of Something Awful.
What's interesting to me is how many people have such long gaps in forum usage. I've pretty regularly used forums for most of my life. Even in the advent of more commercialized social media like Facebook and Twitter. I'd count Reddit (as cursed as it may be) as just another forum/message board though.
A lot of smaller gaming communities have survived or sprung back up as message boards in recent years (examples: Giant Bomb and Waypoint). Then there's always stuff like Something Awful, which is actually where I found a lot of good indie TTRPGs stuff and groups to play with.
I don't think I've regularly used a forum since... junior year of high school? Maybe? So like 2007. I was obsessed with the work of some author and got Involved with her forum for a few months. I used forums all through junior high, though, starting in like seventh grade, and then I fell off them for other platforms.