That is the market deciding. Twitter's market is liberals and leftists, so twitter changes the platform based on their demand. If you don't like this, then you don't like free markets.
I don't particularly like free markets but I have a very specific qualification for Twitter.
If an American platform hosts public officials who use that platform for political purposes, then it should follow that all American citizens should have access to engage, comment and react.
Public officials relying on private platforms for public policy purposes, fundraising etc seems absurd and grotesquely undemocratic.
Twitter’s only duty is to maximize shareholder value like good capitalists without breaking laws. It isn’t breaking laws. It is making a bet that kicking of certain people will help the platform in the long run (same bet that AWS, Google etc are making) If your views are so fringe that the majority of the tech co’s are telling you to GTFO well then society as a majority is voting against you getting a bullhorn. Otherwise they would be worried about a boycott by users/advertisers. If you think the giants have misjudged then I am sure you could find funding for a competing site and infrastructure. Free market capitalism is about allocation of capital in a democratic society not about deciding what the rules of that should be that is the govts job. Please vote!
Strongly agree on public officials using private platforms for policy, but they must have seen something attractive about it. Free people and whatnot...