The issue is he really did need to. Saturn had his crew frozen and Bonney was about to die.
Luffy didn't stay down out of convenience, Oda literally wrote that he hit his absolute limit.
You can argue if Kizaru and Luffy had an all out battle Oda would avoid writing this, but in the canon exchange he decided to go this route to Luffy's detriment.
Luffy didn't stay down out of convenience, Oda literally wrote that he hit his absolute limit.
You can argue if Kizaru and Luffy had an all out battle Oda would avoid writing this, but in the canon exchange he decided to go this route to Luffy's detriment.