Russia for example aims to sow discord. One classic example is the Black Lives Matter movement. This was not a Russian disinformation campaign - but they did propagate views that exist outside the bell curve of the moderate. They push scenes of cops being under siege for the right and racist policing for the left. They amplify the voices of the most angry, the most extreme and the most radical on both sides of the spectrum to create confusion, distrust and societal division.
China by comparison takes a much more subtle view. They choose to erode what they call "civilizational confidence" by highlighting systemic failures, inconvenient truths, or otherwise undermine institutional credibility. When you read an article and find a moderating factor buried in the last paragraph that is the flavor of Chinese action. The general malaise about American exceptionalism failing and China's inevitable ascent stems from their work. Rather than pure division they aim to emotionally exhaust you into "acquiescence from inevitability".
There is hardly a nation on the earth that is not involved in some way in the American discourse - each pushing and pulling to their own aims and individual agenda. Historically there was a sort of Nash equilibrium with Americans caught somewhere in the center. But as the loudest voices, or rather the most well funded, begin to dominate the discussion via social media and covert funding, we are seeing it become increasingly problematic for American democracy. That is why you are starting to see this consensus over 'verification' and 'identification' begin to coalesce. The government, both left and right of center, has begun to realize the long term ramifications of these actors.
So how do you solve that inherent tension between our intrinsic right to free-speech and those who would abuse it to cause us actual harm? An independent, 3rd party verifier with limited scope makes sense - but would that solve the greater geopolitical implications? In truth I've long expected social media like Reddit, Facebook, et al. to formulate a body of their own like the MPAA. But likewise I don't think there is a clear answer here. Do you trust the Tech Oligarchs with this power over the Government itself? This is core to the problem. How do you 'censor' the internet without really 'censoring' Americans? I think this is part of what the last administration was trying to do with the failed "Disinformation Governance Board". And that failure is what has led us to where we are now.
The original twitter thread is right to say this isn't a left-versus-right issue. This is undeniably a censorship mechanism designed to exclude a set of voices from the internet as we know it today. As with the patriot act, they choose to wrap the bitter pill in a bacon-flavored rhetoric of safety and protecting the youth from perverts and degenerates. But what has failed to be acknowledged is the intrinsic cost of having an open society in a world where that openness has become an attack surface. Make no mistake: the goal is censorship. But the solution space to what you call 'the nominal problem' is less trivial than I think you believe.