IMO this boils down to big platforms being pressured to moderate, because some horrible things are shared there, and the cheapest moderation is blindly flagging

IMO this boils down to big platforms being pressured to moderate, because some horrible things are shared there, and the cheapest moderation is blindly flagging words. People discussing things like games get warned/banned/shadowbanned by machines for using banned words, and everyone is getting used to self-censor because the appeal is as useful as a second navel. TL;DR: self-censorship is so prevalent because it saves online platforms money.