Would be nice if forums come back simply because of the searchability. The problem is when they become inundated with users and have too much noise. Maybe it will be just another cycle which will lead back to Slack/Discord after some years and then back to forum after some more.
I think IRC's strategy of having networks and channels on those networks is nice because then most programming languages will be like "well let's just be on this one network". Reddit is this times 1000 given that it's all subreddits on the same platform.
Not perfect for many reasons, but having to sign up to random forums to try and interact with support for, like, Circle CI has always felt a bit silly for me.