In the Past, Oda said that Luffy never kills his main opponents because he considers letting them live to see their dreams ruined a far more fitting punishment.
But the way things are going, no other One Piece antagonist ended up as broken as Kaido will be by the end of the Wano arc. I’m almost sure he’s never setting sail ever again, maybe not even for the final battle.
Kaido’s crew is crumbling from the inside out because none of his men ever followed him out of true loyalty, only due to fear or self-satisfaction. All the other villians either still have a loyal following or managed to recruit new ones like Enel.
Even Doflamingo, despite being a p.o.s, still treated his crew as his family, and they remain loyal to him. Heck, I’d wager even the Baroque Works members who were saved by Ms. Golden Week still await further instructions from Crocodile. But not the Beasts Pirates.
All the Pleasures and Waiters have already turned against him, perhaps most of the Gifters as well, the Numbers are probably dead or out of comission, most of the Flying Six might join other crews after this battle or stay in Wano as criminals/mercenaries, while the Calamities will probably be arrested by S.W.O.R.D or CP-0.
Big Mom is finished with Kaido because of his actions towards the kids in Ebisu.
And even his own son/daughter told him, to his face, that he/she’s joining a rival crew.
