It seems clear that one day, possibly in the near future, tourist won't be the only one at $$$4000+$$$ rating. I think that this raises a bigger issue, though: there are too many LGMs. Of course, this is just an opinion, but I don't think that the word "legendary" should be thrown around this often. For example, wrt chess, Magnus Carlsen and Bobby Fischer are legendary. Hikaru Nakamura is very very good, but he is not legendary. Also, I don't think anyone would consider the current world champion Ding Liren legendary.
To be honest, the only person on cf with true legendary status might be tourist. In fact, we can tell that he is the only legendary one because he has his own rank. If any of the other LGMs were legendary, they would also have their own rank (or something like that to signify true legendary status). So maybe $$$3000-3999$$$ should have a different name.