Read access should be managed on the user level, not the instance level imo. I don’t want to inherit some collective blacklist, I want my own.
For write access, it’s more complicated and I’m not sure what to think.
When an instance has a specific rule, no NSFW for instance, it can’t be receiving that content from other instances and serving it to its users because it breaks its own rules. You might want NSFW content but your instance’s users agreed to that rule, probably because that’s what they wanted out of the instance.
The problem is that read access for a user means the content is cached on the instance of that user, making the instance owner potentially liable if we are talking about content illegal in their jurisdiction.