I don't know what 'the solution' is, but I do sense a precedent being established that I am weary of. Twitter is simultaneously a public sphere where politicians are prohibited from blocking users, but also a private platform where they can be ejected at-will.
I do not know what public sphere means, but I doubt Twitter stops specific accounts from blocking other accounts. I do not see why that is relevant either.
The president of the United States, of all people, has the capability to put an RSS feed on Whitehouse.gov or the president’s personal website anytime they want.
It's a general problem too (IMO): Microsoft/Github mediates FOSS development, Facebook (I'm never going to call them "Meta", I think the rename was a huge dick move by Zuckerberg that pollutes our language and culture. Nyah.) Facebook is Easy-Bake oven Internet for normies and they love it. Smart phones are malls.
No, it's not.
When a public official uses their Twitter account as an official channel, that account becomes a limited public forum from which users cannot be blocked for reasons that they could not be excluded from official government fora more generally (e.g., viewpoint discrimination is not permitted.) This is not a restriction on Twitter, but on the conduct of government business by public officials that applies wherever and whenever they conduct such business.
There is no such notion - private companies have to obey the laws of the land like anyone else.
Platforms like Twitter have the right to ban politicians on the basis of the rights of private property and freedom of speech and association. The same rights that allow restaurants to eject people for "no shoes, no shirt, no service" and allow radio stations and newspapers to choose what and what not to publish, and me to tell Jehovah's Witnesses off. I don't know why this suddenly makes people feel uncomfortable, when these rights, and the ability of private enterprise to exercise them, have been part of the basis of Western liberal democracies for hundreds of years.
The inverse of this would be to give carte-blanche ownership and rights over all property to politicians - including social media platforms, that supersede the rights and desires of the platform owners. That it would be illegal to ban any politician from any private property under any circumstances.
I believe it's a good thing that the President of the United States has no more right to act the fool on Twitter than you or I should. Twitter is not, and should not be, the sole nexus for all global political and cultural communication. It's a microblogging platform, ffs, the only reason it "matters" at all is because one specific paranoiac President didn't trust his own media apparatus.
It's a convenience. It's certainly useful, but it isn't necessary.