ERP is gross but more than that, just incredibly cringey, which is it's main offense IMO. I don't think it can or even really should be banned though, as long as the people doing it are doing it in private and are both legal adults. However, I do wish the game would stop allowing people to advertise their 18+ nightclubs in game chat. I hate teleporting into limsa or gridania and some jackass from another server is advertising some ERP nightclub, really obnoxious behavior. You aren't going to get anywhere saying this stuff to ff14 players though man, this is one of the most degenerate fandoms for a game out there, and most people completely lack self awareness and aren't capable of engaging with anything critical of their behavior, so you shouldn't even really bother.