The only reason Facebook was at all successful is that they made it easy to migrate over from MySpace.
Before Facebook people weren't locked into their social networks. In the early days of BBSes you were mostly on your local BBS, but you could sometimes communicate with another BBS if your BBS was part of FidoNet. When instant messengers like ICQ, AIM, MSN Messenger, etc. became popular, it was common to use a unified program that logged into all of them at once. But, already there was corporate consolidation. BBSes were often run by people out of their own homes, or at least by hobbyists. The early messengers were all commercial products.
Then there were the early social media websites: SixDegrees.com, Classmates.com, Friendster, (LinkedIn), MySpace, Orkut, and in 2004 Facebook. At first Facebook was closed to anybody who wasn't a US university student. You even had to have an email address from a US university to register. But, when they wanted to grow, they made it easy to migrate from other sites, especially MySpace. They released a tool that allowed you to basically stay in touch with your MySpace friends from Facebook, but not the other way around. That slowly drained people away from MySpace until it eventually collapsed. These days, thanks to section 1201 of the DMCA, if you tried to release a tool that allowed people to migrate away from Facebook, you'd be nuked from orbit.
Now, every social media site is a walled garden protected by a moat and an electric fence. Every one is owned by companies worth more than $1b. People can't leave because the FOMO is too strong, but they don't want to stay because the sites are pure shit. You see that especially with Twitter. It is absolute shit since Musk took over, but many people feel like they can't leave. And, when people do leave, do they go to Mastodon, which isn't owned by a corporation? Nope, they mostly go to Threads, owned by Meta, or Bluesky, owned by a lot of the same people behind Twitter.
Unless the governments of the world step in and either break up the tech giants, or require that they are interoperable, I don't know how we back out of this shitty situation.