You could probably get away with banning all common english words as usernames if you wanted to.
Or put all user pages under some top level path and then you never need to ban anything as this problem becomes completely moot.
Even if you don’t ban all words, there are some you should filter:
• <https://ldpreload.com/blog/names-to-reserve>
• <https://xkcd.com/1963/>
Or put all user pages under some top level path and then you never need to ban anything as this problem becomes completely moot.