Someone shouldn't be able to have the @admin username
It's confusing for new users, and this instance in particular has 7k users but no interactions. It's a bot army, with the top user being called @admin.
I think some form of blanket ban on certain keywords in usernames should be used. Admin being an obvious one, but I'm sure a lot more would also be problematic.
I think they could put it in the Lemmy source code that an instance won't display or take comments/posts from anyone with those usernames. So even if someone removed that restriction from their own instance, they wouldn't be able to post on any other instance that has that feature enabled