It's time to accept that titles are what they are: titles.
Was Whitebeard, the World's Strongest Man, actually stronger than Roger, the Pirate King? No.
Was Whitebeard, the World's Strongest Man, actually stronger than Kaido, the World's Strongest Creature? No.
Is Mihawk actually the most powerful character in the series who uses a sword? I kind of doubt it at this point.
Titles in One Piece are for flare. "In a 1v1, always bet on Kaido." And, who won?
If Shanks has Roger level Haki we clearly know why Kaido didn't make it to Marineford now.