Because it's the BS Deus Ex Machina that the "hero" can have as much "respawns" as he needs, but the "villain" doesn't.
Luffy is just gonna play for the "Kill Steal".
Disgraceful.
Freaking author legit can't share Luffy's glory for any reason. Gotta drag the freaking arc until Kaido is weakened enough for Luffy to "solo him".
Luffy vs Life-support Kaido.
E-P-I-C. GODA.