Levitate is a very powerful save or die spell against most creatures at lower levels. It's better than hold person, especially in the hands of a diviner with portent. It's basically save or die, and not restricted to humanoids. Plus it has other utilities beyond just crowd control.
Hold Person becomes better later on as the casters spell DC goes up and it can target multiple creatures with higher level slots. At very high levels due to flat saving throw bonuses not much is making DC16+ wisdom saving throws very easily. There's still a lot of humanoids in the game at higher levels - any NPC enemy for example.