Flame off King took attacks that'd make even Kaido rethink his life's choices. Those two aren't even remotely the same. And Wano Luffy and WCI Luffy aren't even in the same stratosphere so you're not making a point. Katakuri's attacks were factually weaker than WCI Boundman as noted by Luffy himself while Wano characters' attacks shits all over even Boundman, forget Katakuri.
Zoro only used 2 ACoC attacks. Onigiri which King tanked and Dragon Damnation thay 1 shot King
Flame off King is a glass canon compared to Luffy