Here's the thing. You can't force people to use a social network. Literally no one cares about this stuff.
There's a reason why there are like 5 social networks while thousands of people want to "make the next Facebook."
If Meta is a threat, then ban it. People will cry and maybe then new alternatives may emerge. But you still need skilled people who'd rather work for you than accept Facebook's $400k offers. Good luck with EU funding.
Make a social network for politicians and journalists, also open to everyone else who then wants to comment on their discussions, but with their real identity.