Certain One Piece events come around to let fans know what the power hierarchy looks like. Sometimes, it's a simple matter of one character establishing dominance by beating another. There are also more nuanced instances of characters holding their own against superior opponents or performing similarly impressive feats of strength, speed, durability, etc. Whatever it is, fans will use it in endless arguments over who's the best and who can beat who in a fight. Such is the nature of a battle shonen.
Source：https://www.cbr.com/one-piece-chapter-1091-power-scaling/
