and you think the news of Shanks beating Kid or Teach beating Law won't be public?
p.s
also people claim Shanks bounty is low cause he is peaceful
but the fact that Gorosei KNOW he will never try to take over the world (unlike Kaido)
should be a factor too
but as you mentioned, not all of Kaido's feats went public ...
so bother Shanks and Kaido had a chance of surpassing at least Whitebeard bounty
This is the point, we will have plenty of arguments to say that Kaido and Shanks' reward could have surpassed Roger and Whitebeard's, especially Whitebeard's. However, the narrative did not allow for that, plain and simple. Apparently, only Luffy and Blackbeard have this privilege, which is ridiculous.
For Kaido, he can use the excuse that the events in Wano (Kaido's feats) didn't leak, although the government and the navy clearly knew that a war was taking place. However, for Shanks, he will simply apply delay and start with Kid here. Shanks defeats Kid and doesn't receive anything for it, Kid and Killer.
Before Kaido's bounty was revealed, he had defeated the 'Fifth Emperor Luffy,' and the marines knew about it, but no increase in the bounty was mentioned. I mean, Sword and not necessarily the marines, but if the marines knew about Kaido and Big Mom's alliance, they knew about Luffy's defeat...
It is very difficult for the Yonko to receive an increase in their bounties; the only ones who continue to see increases are Luffy and Blackbeard.Apparently, after reaching the 4 billion Berries mark, not just any feat leads to an increase in one's bounty. Defeating someone with a bounty of 3 billion or 1.5 billion is common for someone of that stature.