> I saw racist and sexist posts personally

Honestly Reddit in general could be taken as "racist and sexist" by an outsider. By an outsider. The humor tends to be sarcastic, tongue-in-cheek, over-the-top, and in-group. For example any references to /r/pyongyang can be written off, 99% of the time it's part of a dedicated running joke that's not intentionally malicious. Pao as Hitler is jarring? You seem naively unfamiliar with Reddit.