The market of ideas fails under capitalism. The market of ideas is denominated in votes, but capitalism requires it to be denominated in dollars. The market of ideas also fails under governments and corporations who pay thousands of people to work covertly and overtly to eradicate ideas.
The problem isn't Capitalism. In Capitalism we can simply buy our services and anyone who can fund can play.
What is happening when a bank refuses to do business with someone, when App stores ban a twitter clone and prevent sideloading, is not Capitalism. It's ideological. It's about service to an end outside just capital.
Capitalism is the only system that freedom of speech can exist under. No Communist or Socialist author has ever entertained a freedom of speech concept - it is contrary to a centralized government. Such systems can not even handle mild political dissent and must (both in the theoretical and practical) literally kill or exile anyone pushing against the central authority.
Capitalism can always tolerate disagreement because disagreement is profitable.
>Capitalism can always tolerate disagreement because disagreement is profitable.
Eh, that depends. The US in particular like to 'two party' problems. Capitalism loves two sides in problems, but that is very problematic if a problem is multi-polar and not bi-polar.
You're also confusing socialist/communist with authoritarian. Capitalist systems are completely fine with being authoritarian if its profitable.