I understand your argument, and I don't disagree with it. Nor do I agree with the absolutely ridiculous reasons the government has given for the ban. It's the end result that doesn't bother me.

As for federated sites, they aren't as threatened as you might think. Sure, the government could shut some of them down if they tried. But that's only true for those that are hosted and ran by people in jurisdictions that the US government can affect. That's the strength of federation. Not only can platforms like Lemmy not turn out like Twitter, since you can defederate from instances that allow things like white supremacy, effectively purging those types of people from the fediverse at large, the decentralized nature of the system means that there's no practical way for any one government to take down the entire ecosystem. A good example of governments trying to take down something they collectively hate, is piracy. Even united behind the cause of capitalism, and with the billions of dollars of the recording and motion picture industries behind them, nations across the world have not had great success in stopping piracy of any kind, mostly due to the patchwork nature of takedowns. I don't have any fear that the US government would be any more effective in tackling federated platforms.

I would go so far as to say that federated sites are the only social media people should be using, because it's much easier to control things like disinformation, since the power in adjusting the flow of information isn't centralized to one group with one agenda. Some would say that just creates an echo chamber, and for some instances that's true. But unless those admins defederate from everyone, their users are going to be exposed to viewpoints that disturb that echo chamber, from places they don't have power to control.