Censorship, beyond what’s required by law, is doomed to fail.
So you can lose credibility two ways, one by not doing any censorship because people on the internet will be the worst if you let them. Doing too much censorship is also bad because people don't like that either. Of the big causes of censorship currently, I think of things like youtubes copyright claim process and how that is routinely used as a censorship backdoor by anyone - including the police. Sometimes its not even for any good reason and done by unthinking bots. This is banning more perfectly fine content than anything the government has done. I don't understand why there isn't more pushback against that process to punish people for frivolous claims.
If you look at every attempt to create "The Uncensored Free Speech Version Of [ANY_SERVICE]," they all, inevitably turned into a 4chan-like trashfire. You've got to have some kind of moderation.
So whats changed?
Well, I have my thoughts, but one thing is for sure, as soon as the platform itself tried to start moderating, that's when things really started changing.
Now that the entire population uses it, the average IQ involved has plummeted, and the political and social payoff for manipulating it with inauthentic content is huge.