Maybe I'm lucky in the instance I chose or the content I like being uncontroversial, but this isn't my experience at all.

I've heard of instances carrying a lot of Nazi content being banned, and of instances choosing not to re-host adult media (which makes the interface a bit worse, but doesn't actually block you from getting that). But most admins from what I've seen are pretty clear on this in the about page of the instance.

70% seems like a wild claim.

I have had content I like being removed from major social media platforms, like reddit and tumblr.

Also, if you choose an instance and it gets shut down, you just start another account. This isn't serious business, it's social media. To me, complaining about having to choose an instance to start is like complaining about having to choose a class at the start of an RPG.

Personally, I really love mastodon as a platform and I don't understand all the hate it gets here.