Bro I thought your problem with Twitter was that they banned you for stupid reasons, not that the government was spying on you.
The owner of a piece of property has a right to restrict freedom of association however they want on their property. If that's not problematic, then what's the issue with using ActivityPub? Or a Discord? Or an SMS group-chat? Or even chatting on a Minecraft server?
These are all centralized social media services, are they not?