My answer is BAD writing
Kaido went from "don't know how luffy can defeat kaido, it wont be just some punch" to kaido being defeated by a guy who had trouble beating YC with a big punch
Big mom went for intelligence collecting master mind mafia don type to a buffon who get rolled around by niko robin.
But maybe i guess unlike shanks who although was in one of the strongest pirate crew when he was a kid. He did not have super human strength like kaido and big mom when they were kids.
Thats why he has possibly the strongest haki in OP right now. Like luffy he had to progress without a DF his haki became monsterous.
He use to go 1vs1 with the strongest swordsman so unlike kaido and BM he developed fighting technics. How many moves did kaido have in his fight with lufy? It was always that dumb club and dragon form. I expected him to go awaken and the two tear up the sky with their final attacks!!!
So maybe kaido and big mom didnt have to improve of their strenght like luffy, zoro, shanks and maybe even roger. Thats why they never went beyond yonko status. Think of it like how in DB freeza was born with a huge potential but never puts any effort to get stronger like goku
Kaido went from "don't know how luffy can defeat kaido, it wont be just some punch" to kaido being defeated by a guy who had trouble beating YC with a big punch
Big mom went for intelligence collecting master mind mafia don type to a buffon who get rolled around by niko robin.
But maybe i guess unlike shanks who although was in one of the strongest pirate crew when he was a kid. He did not have super human strength like kaido and big mom when they were kids.
Thats why he has possibly the strongest haki in OP right now. Like luffy he had to progress without a DF his haki became monsterous.
He use to go 1vs1 with the strongest swordsman so unlike kaido and BM he developed fighting technics. How many moves did kaido have in his fight with lufy? It was always that dumb club and dragon form. I expected him to go awaken and the two tear up the sky with their final attacks!!!
So maybe kaido and big mom didnt have to improve of their strenght like luffy, zoro, shanks and maybe even roger. Thats why they never went beyond yonko status. Think of it like how in DB freeza was born with a huge potential but never puts any effort to get stronger like goku