While that’s true, I don’t believe it to be a fundamental property of the medium or federation in general. I think what we are experiencing is the result of lack of mainstream attention and traffic.
The people here are much less demographically diverse than the public at large, and have intentionally sought out this space and others like it, so they have more of a sense of ownership and community about it. The more attention it gets, the more the demographics will change to reflect the broader public, and the more it will become like a public space, complete with all the ills that come with that, like advertisers vying for attention, shills posing as enthusiasts, and influencers saying what will get them the most followers, rather than what they think.
I believe it would take extensive moderation and amazing tools to keep places like this the same as they gain users. I haven’t ever seen a community survive that kind of growth and retain its original spirit, but I also haven’t seen one with no profit motive. If we can get the moderation tools where they need to be, there could be hope!
I think that’s trying to solve the wrong problem.
If I had awesome moderating tools, identifying and deleting comments that violate the policy would be effortless. I would not need to ban a person, which as you aptly point out, can reappear forever. But, I can ban all of his violating comments, which are, after all, the true target and violation, not the commenter.