I feel like this censorship is mostly caused by centralization of information on closed/proprietary platforms, and the stakeholders of these platforms put it upon themselves to censor content they deem inappropriate or incompatible with their bottomline.

People can say that these platforms are privately-owned and freedom of speech is only about government censorship, but where do you speak when these platform are well established and chances of dethroning them with a decentralized and open alternative are slim to none?

Social media is not social, it's corporate.