What u guys mean by fail? The Alliance being defeated, moving to other island and comming back after some time to do everything again? lol stop watching too much YouTube.
Kaido beating Luffy again and them they having the final round in Wano mainland can happen, but its not the raid failing. Some of the F6 comming back and fighting again can happen, but thats also not the raid failing. Even the CP0 joining the War is not failing, its just a fouth party joining, but the raid failure means complet defeat from the aliance side, not just some characters being out of combat for a time.
A lot of plot threads like Hiyori, Tenguyama, Road Poneglyph, Numbers, Kaido FB, Zoro past, etc dont need the raid failing, they will just be develop later in the arc, while other are just desilusional from fans like Franky weapons, BM Pirates and other things that dont have impact. I wouldnt doubt if the BM pirates are just defeat by the WG fleet and Oda use them to hype the CP0, because what else the the loser side characters from BM crew can do here? The main characters from the crew like Katakuri, Puddind and even Tamago aren't here, the only relevant character of the crew here is Perospero, who is alredy in the battle.