The issue is in some cases “they” (FANNG, Reddit, Twitter, etc) want to be platforms like Facebook saying ads aren’t their responsibility, and in some cases are acting as publishers by censoring otherwise legal content they do not like or agree with. There are memes that will get you instantly suspended from Facebook, while you and Facebook argue no one could possibly monitor content!
It shouldn’t be that the giants get to be both. Legally they are provided protections against content on their system - but historically this only applies to platforms where the content is entirely unfiltered. Think if your telco cut the call when you said the words “Jeffery Epstein didn’t kill himself” as a fictitious example, they shouldn’t get liability protection for things people say if they’re going to curate the content like that.