The most common excuses I've heard are:
- Kizaru ran away the whole time and never actually fought Luffy
Even though this page exists.
So the argument is that Kizaru only won due to matchup and would get clapped by anyone else, while Luffy would destroy any other Admiral because he would not get tired by them the way he did with Kizaru.
- Kizaru being mentally nerfed didn't nerf him that much even though we've seen multiple cases of mental nerfs fucking over a character - hell, that's what the whole Water 7/Ennies Lobby arc was
about.
Or that Luffy was:
- Holding back his ACOC even though his friends were in danger
- Literally nearly dead from hitting the EH laser barrier which Bonney survived.
- Exhausted from previous fights even though he had a night to recover
- Flat out nerfed because Oda said something about having to put obstacles in front of Luffy due to him being strong, back in Fishman Island
- Never all that strong, he only beat Kaido after the latter was exhausted after fighting Yamato, Scabbard etc and is therefore the second weakest Yonko after Buggy.
Garp is technically a VA you know. And so were the C3, Sengoku and maybe Dragon.
Also Doll is best girl, Momonga best boy, Onigumo top 1 spiderbro and Vice Admiral Chins is a cool Kaiju reference.