But also when they would ban someone, they would do so from every single community on their instance, including ones that you've never even heard of.

And then never bother to so much as tell you about your being banned.

And also deny you the ability to appeal or ask questions - e.g. Reddit has both a modmail and the ability to continue discourse directly in a post that has been removed from a community listing. Which as a former mod I would use to communicate rejection reasons and sometimes we'd go back and forth for days talking about the subject further, e.g. ways that the newcommer could modify it as to not piss off the old hands in the community (e.g. NSFW is allowed but must be properly labeled or some such).

Oh, and soon a change is going to give lemmy.ml veto power on what communities are allowed to be suggested to new instances - and being baked right into the code so there is no way to change that - rather than use a third-party listing. Edit: this proposed change has already been walked back, and while still using a centralized source for that information, at least makes it configurable by the new instance admin rather than hard-coding lemmy.ml as the singular authority (except as the default option).

I find it highly ironic that in some ways Lemmy, in particular .ml, is more authoritarian than even Reddit.