Very few people are able to parse the blockchain data without using a front end provided by others. Since front ends are all prone to censorship to some degree, that effectively censors the blockchain.
My point is that it is false to claim that suppression of posts isn't censorship. Flags are censorship, since they suppress posts. Demonetization on Youtube is censorship, even if the content isn't deleted. Deletion of content on Youtube is censorship even if content remains up on Bitchute. Censorship isn't either complete or nonexistent. It's impossible to eradicate information totally, and therefore censorship is any attempt to reduce the availability of content, and that includes flags.