Wrong, handsome villains are usually more powerful than the ugly ones, looks is used to establish power scaling in pretty much all anime and cartoons (or tv shows, movies, etc), its how we do it in all media
Notice how grotesque an villains "lesser transformations" look in comparison to his "final form"
Go watch any anime, the more well proportioned and "humanoid" a villain looks in their transformation, the more powerful that state is, and "failed experiments" or "inferior villains" always look deformed and/or have crappy proportions (and are always uglier)
Also one piece is blue pilled nakama power trash, its a few steps away from being fairy tail