I lived through those early days, and although they were glorious, those boards, and forums, and ICQ chats weren't filled with friends and family.
MySpace was the first place where everyone was. It was the first time in history where you could go find out what happened to all of your old friends and rekindle a relationship if you wanted to.
I remember going through basic training when the Drill Sergeants told us we'd make the best friends of our lives, that we'd never see again. And that held true for 10 years after I got out. Then suddenly MySpace became hugely popular and I found them all again! Because of Facebook I'm still friends with several of them today.
Facebook got really lucky with the timing of their public launch. They still kind of just sat around being empty until MySpace started massively changing the platform under new ownership from NewsCorp. I think that acquisition was the worst in history up until Twitter.
Anyways, in their infinite corporate wisdom, they wiped everyone's profiles. Like seriously, WTF? They deleted everyone's pictures, all of their blog posts, comments, and just about everything. Talk about not understanding what they bought. They did release a tool to get your pictures back, but why the heck would anyone trust the site after that. People were already checking out Facebook, so they all just jumped over there. Plus the clean design, with lots of white space (which is completely gone now), was very Web 2.0 and people liked it.
Anyways, like I originally said, and like you confirmed, that era is over. We both know the government is never going to split them up, and even an exact clone of a service today would fail. Social sites need people to succeed, and people don't have any interest in creating a new community when there's all of these ready-made communities that they already understand, regardless of how bad they have become.
The only reason TikTok succeeded is because it had backing from CCP and basically infinite money to market and attract new people. No start-up would ever have those types of funds these days. If somehow through a miracle a start-up did acquire enough funding to be a threat to meta or Xitter, then the billionaires at the heads would make an irresistible offer, buy it, and kill it. It's over. The free Internet is dead.