The point which is sometimes missing is that it does not matter if you believe a user (i.e. Donald Trump or anyone to whom these policies may apply) deserves to be banned or not.
What matters IMO is that a certain individual lost access to a service or product based on a ToS (not the democratic law) of a company which may change at any time to reflect the corporation's interest (morally or otherwise). Also, these companies happen to intertwine with today's social fabric.
There are no checks or balances on the amount of power these companies hold. Even if you believe, for example, Donald Trump deserved to be banned, you might think for yourself what will stop them to come for you next? Do you believe companies play a moral rule book?
Imagine you lose access to your important email address, or your phone number (which is perhaps operated by a private corporation). Do you also have a podium in your house to fix it?
Now you see where I am going with this. I don't want to take a side in a political argument. That's not the point here.
With all that said, it's hard to not address the elephant in the room. Which is the "free market". Unfortunately, this is a difficult problem to solve which I don't have the expertise to propose a solution for. But what I can observe is that this phenomenon is not new and not exclusive to tech companies.
Take banks, for example, you get a credit score that is shared between banks and you can be denied service. If you make insurance claims your premium may go up even if you switch providers. You can be denied coverage with a pre-existing condition. An airliner can deny you service based on a policy exclusive to them, a company abuses your private data, etc.
In most of the instances I (an individual), have been denied service from a powerful minority and they decide to do so following their interest (fair or unfair).
While there are a ton of arguments by different political, philosophical, and sociological views for these examples pro/against, I wonder if this problem can be solved in the current system without some fundamental changes/enhancements?