Instead of thinking, "holy shit Luffy is 1v1-ing Kaidou out of his ass, what an asspull", we should think otherwise "holy shit, the Scabbards and the 5 Supernovas really did some work on Kaidou, they weakened Kaidou enough for Luffy to 1v1 him, especially that Ashura of Zoro"
See, everyone wins in this situation. The world finally finds peace.