All platforms censor their users. Some more than others. I've censored people on steemit by flagging spam in the comments during a contest I hosted that asked for users to comment. I've been censored by the PAL network while not breaking any specifically stated rule, but because someone didn't like what I was saying.
Of course YouTube censors people. If you're promoting alternative platforms to YouTube then why not tell us why they won't end up doing the same thing?
Freedom of speech and expression means being allowed to say things people won't like. People with more power than you will do what they can to censor you whether or not you make sense. It'll always be like that unless you do away with freedom of speech.