As someone who very much "grew up" on vbulletins and irc for better or for worse, I miss this.
But also... I am not sure if them going away is a bad thing. Small message boards only really worked when people, generally, did not care about moderation. Specifically moderation of hate and the like. Because when you are "a small group of friends', it is a lot easier to ignore the guy with "weird vibes". Same with the people who went out of their way to "keep women out" by insisting on making their signature images so horny that even a diehard Fairy Tail fan would blush.
But, as many of us saw, as those boards get larger? Now you need real moderators. Just having the guy who hosts it in his parents' basement delete the worst stuff no longer works and now they are asking their friends to be mods. And you basically get the same problem people still complain about on discord where you get very cliquey communities and incredibly biased moderation.
And it inevitably leads to boards either becoming a cesspool of hatred, selling the board to an internet company, or just saying "Fuck all y'all" and shutting it down overnight.
And even stuff like legacy tech support or technical knowledge? Those are already a mess of the top result being some greybeard asshole talking about how OP is a jerk and this is a common problem and they should search for it. Or we have the stack overflow problem where the accepted answer is actually wrong.
But also? For living software, bugs change over time. And plenty of times I have found exactly my symptoms/behavior and... it is for something that was fixed three years ago. So I am now looking at a different bug with the exact same symptoms and basically every search engine is worthless.
And... going back to the moderation aspect: One of the biggest Looking Glass Games or Unreal fansites in existence was still MAYBE a hundred or so people who knew it existed and a couple dozen who cared enough to hang out at the forums. Now? The fansite for a mod for the latest Microprose game is one google search away and might get name dropped by an influencer and have thousands of people swarm overnight. Let alone anyone who gets targeted by the latest hate campaign. There are no "small" communities that aren't private and spun out of larger ones.
So... I dunno. I very much miss the good old days. But I also increasingly understand those weren't all that "good". And communities are so ephemeral that they map well to a discord or even a reddit that people rage delete a few months later.