If they have editorial capabilities, they should be liable for the content which is uploaded to their site (like any editorial website would). Currently, the U.S. government has created special laws which prevent this.
If they only want to be a "plataform" for people to upload or discuss content, without any form of liability for the content that is uploaded there (such as copyrighted material), then they shouldn't be able to have editorial powers.
A special protection from government isn't "capitalism", its corporate cronysm. Capitalism is about getting government out of the economy.
When the various social media companies began they were classified as providers, similar to a phone company, and according to the law (preexisting) they have special tax status because of this. They are not an editorial category, just providing the service, like the phone company who provides the line but doesn't not interfere with who you can call or what you can say. And, again according to this law, they have protection from liability as to what is said by someone using the service they provide.
Recently, however, as they have grown larger and actually gigantic, they have taken onto themselves the power to determine who does and does not use their service, what they can say etc.
Which is why Trump has been planning to change their status, removing them from protection of that law, from provider to that of an editorial service, like for example a newspaper, who can be held reliable for the opinions and articles they publish. And their advantageous tax status would disappear and they would be taxed like editors, newspapers, etc.
At the moment they are flexing their muscles with the idea that the left will be in power and allow anything, so long as it censors the right, conservatives, Trumpers, etc.
Twitter still has postings from this summer where various politicians in effect called for violence during the riots in Democratic cities, including Harris. And they are not being removed and don't run any risk of being censored.