oda is clearly doing it to parallel the kaido oden fight
but instead to still have luffy win
in essence
its surpassing a predecessor
Luffy definitely ain't winning right now. He's gonna need another round, that's for sure. Everytime the climax of a Luffy fight draws in before he ultimately wins, all the other plotlines would be resolved and the arc's doomsday tension would be at it's dramatic peak, f.ex., the Birdcage in DR was really close, the SHs reached Cacao Island and it was Luffy's turn to keep up on his side of the promise in the Katakuri fight, the Buster Call had started in EL etc,.
Right now in Wano, there are tons of plotlines left to be resolved and the people of the Flower Capital
don't even know that an Island is gonna fall on them.
It's gonna be atleast another 10 - 20 chapters before Kaidou is defeated by Luffy, probably after
another powerup (DF Awakening if I have to guess).