Twitter has no mandate to provide everyone with a platform anymore than NBC does. NBC just has limits because of production costs and the sale of airtime for everything it hosts... NOT because they are making a stand to limit speech. Those are purely business reasons, not political ones.
This is different from refusing to serve black people. Because that much is on the basis of who they are. Which is unlike the basis on what someone does, which is why someone who comes into a store without pants or decides to defecate on the tables can be banned from a private business. There is a right to refuse service on the basis of things other than the race you were born with.
People don't have the choice to be born black or not. But people do have a choice on whether to egg on people to violently overthrow a government building or not.
No, you're too quick in your reasoning.
What I meant was that in both instances a private business offers something (be it a social media platform, be it food).
In both instances that private business decides to not offer their service to a certain potential client.
The question (which you answered above) then becomes on what grounds they can decide to do so. As you rightfully say, they cannot decide to do this based on the colour of someone's skin. A restaurant choosing not to serve someone, will have to demonstrate good reason for doing so or they'll open themselves up to law suits.
The exact same thing goes for Twitter. Imagine if they randomly blocked Biden earlier this year. They'd effectively take away part of his campagain. If Biden would have gone to court and Twitter could not show a good reason to support their decision, I'm fairly confident the court would have told them to allow Biden to post.
This whole notion that private businesses have limitless freedom is flat out wrong. If you decide to offer people a social media platform, you will have to play by certain rules.
So no, Twitter can't just ban Trump, because they're a private business anyway.