I don't really see a problem with an instance banning large numbers of users. The ability to make exclusive spaces is part of the fediverse's design. Suppose a queer space kept getting flooded with homophobic users, or a Muslim space got a bunch of people shitting on their religion, or something like that. Naturally, such spaces would have a higher number of bans. That doesn't necessarily show an "echo chamber" especially since users of such communities may be federated with other communities. People complain about censorship on .ml creating an "echo chamber" but half the time I'm arguing or discussing things on other turfs like .world. The idea that those sorts of enclaves or exclusive spaces shouldn't exist, as is implied with the framing here, is to impose what us evil, dastardly "authoritarians" sometimes call ["the tyranny of structurelessness."](https://www.jofreeman.com/joreen/tyranny.htm) No one would have a space to discuss things outside of the most prominent, hegemonic view, which would more easily sideline and overwhelm other perspectives. As an example, I once frequented an utter cesspool on Reddit called r/CapitalismVSocialism, which was created and promoted by An-caps and where that perspective was prominent (though not exclusive). I found it was virtually impossible to have a discussion with anyone about anything, because even if you weren't talking to an An-cap, they were always there waiting to latch on to some turn of phrase and use it against you, and everyone was too preoccupied with countering their nonsense to reach any kind of high-level discussion. I eventually got fed up with that and found that my beliefs were more challenged by going to explicitly leftist spaces because we had shared assumptions and were speaking the same language, and didn't feel the need to be as defensive. I was never going to be convinced of anything by the An-caps and all talking to them accomplished was pissing me off. The fediverse's design is actually quite brilliant, because you can have a space to discuss things substantively among like-minded people while at the same time interacting with other groups.