It seems people forget that bigmom had the opportunity to kill law and kidd but she stupidly decided to go and assist kaido who never needed her, instead of finishing her opponents, if you want to bring up kaido not killing luffy you should remember 3 things
1. the first defeat he tried to use luffy but bigmom never tried that as see thought of them as a genuine threat
2. the second defeat of luffy (not a real defeat)- the yonkos were still fighting and luffy was protected by the remaining 4 sn
3. the 3rd defeat (not a real defeat)- luffy was protected by zoro
4. the fourth defeat- kaido genuinely thought luffy was dead so he had to clean up the rest of the alliance and he actually never even cared that bigmom was defeated that was the amount of confidence kaido had. so you can say that kaido was the main bad guy which should be obvious
and from reading the fight it should be assumed that bigmom was at her full power even if she never used advcoc (it should be canon that bigmom can't use advcoc consistently since oda made sure to not make her use it all h could have done was at least show her use advcoc attacks on kidd or law and allow them to tank it at least once but no he did not allow her to use it)
1. the first defeat he tried to use luffy but bigmom never tried that as see thought of them as a genuine threat
2. the second defeat of luffy (not a real defeat)- the yonkos were still fighting and luffy was protected by the remaining 4 sn
3. the 3rd defeat (not a real defeat)- luffy was protected by zoro
4. the fourth defeat- kaido genuinely thought luffy was dead so he had to clean up the rest of the alliance and he actually never even cared that bigmom was defeated that was the amount of confidence kaido had. so you can say that kaido was the main bad guy which should be obvious
and from reading the fight it should be assumed that bigmom was at her full power even if she never used advcoc (it should be canon that bigmom can't use advcoc consistently since oda made sure to not make her use it all h could have done was at least show her use advcoc attacks on kidd or law and allow them to tank it at least once but no he did not allow her to use it)