If Shanks Wi-Fi doffed Kaido then :
1- Kaido is unredeemable and ahould be thrown away as a character.
2- Oda is a liar and a hype bitch with nothing to show but empty hype.
3- That would destroy all the very few powerleveling remaining.
Oda has no benefit doing that...
Read that again and tell me how you feel about it yourself?
1) Kaido was scared of Oden. Kaido's intro was just to hype him. Man never wanted to die. If he wanted to fight strong opponents he should have faced other Yonkos. At the end, it was implied that he was also waiting for Joy Boy (when he said you could not be Joy Boy either).
He wanted to start a war, but never went out? Staying in Wano, for what? Why wait for Joy Boy? Kaido's character was already all over the place.
2) Oda can be a liar, hype bitch, and empty hype creator.
But does it contradict his style so far? He has been like this since forever!
3) But Shanks WiFi haki already destroyed the powerscaling. Blame Oda (or GB for acting like a bi**h). Shanks did the same against Kid. We have never seen CoO being used like that.
No benefit? He made a movie about Shanks and earned a lot of money from that. And it seems readers loved G5 transformation and Luffy's win against Kaido (through a bigger punch).
Let's not go down this rabbit hole.