They don't have to be perfect. They don't have to save the world. They don't have to cure cancer. Any improvement is an improvement.
Life is not binary.
If twitter created some arbitrary rule like "We're going to fact-check all state/government personnel.", then the state/government personnel would just change platforms.
it's a real issue -- it's potentially more dangerous to push politicians to lie on platforms that fact-checkers can't respond and provide feedback towards, and if twitter starts playing hardball against politicians that's exactly what will happen.
A ton of small echo-chamber communities that splinter off as a result of perceived hostility or discrimination from twitter (but really any social media group) and the general public may be more hostile/dangerous than having these groups of people being vetted by the public at large constantly on twitter or other popular platforms.
Meanwhile, I make the claim that the echo chambers will stagnate rapidly outside a big platform. The echo chambers need constant exposure to gain new ideological members. If left to a private-club-platform, they will not showcase themselves.
Note that there is a strong adherence to the YCombinator’s code of conduct on the current platform - but we come back to discuss ideas here, not to a not-vetted forum. By making the level of adherence to fact checks, discussions will improve.