I legit never got what was supposed to be hype about hearing "this guy got his ass whopped 7 times, and was caught 18 times" in the context of the story. Makes for a nice bit of theory crafting in the community who it was that defeated him, sure, but as a hype tool for the guy that shortly after this announcement is billed as the world's strongest creature it's just really weird lore.
Its not even like we should be impressed that he survived all those times either. We now know Kaido alongside King were a lab rats of the WG. That's why Kaido has yet to be killed by them. He likely is too useful due to begin special. We know for a fact that if they REALLY wanted to get rid of Kaido unless he is literally completely immortal (which as of now I would not assume since he just seems to be stupid tough) there are several ways to get rid of him that were deliberately not done.
You would for example assume if the Navy or Government REALLY wished him dead, they would have just force fed him another fruit. They had enough fruits lying around that somebody like Spandam got two of the damn things, so they ought to have enough for a job like killing Kaido if they really wanted too.