Because Oda doesn't want to show too much before the under the rooftop actions is over.
Once it is, Kaido will start flexing and Law and Killer will be goners very fast, Kidd will have 1 chapter to hype him up and then he will be a goner too the next chapter.
And finally it will become the straw hats show again and the fight will take another turn, nice moves from both sides, nice actions, powerful attacks. we just have to wait until the non relevant SN get wrecked.