I mean, it's not as if Whole Cake Island had several panels where people said: "Wow, Sanji is as powerful a Germa even without a raidsuit", "How strong", "As expected of Germa" ... oh wait
and those people contributed to Sanji’s bounty? What about Sanji actually beating someone infamous? Or doing anything that can actually give him a bounty raise?
Don’t be mistaken my guy, By a third of the way through WCI, I was of the mind that Sanji was gonna BEAT all the Vinsmokes 1 v 4 to establish his dominance since I knew they were weak. But he didn’t. He baked a cake.
His bounty is only because of his father. That’s the beginning and end of that. Don’t worry, he’ll actually get a bounty increase from his actual actions in Wano after beating Queen.
And then we shall see how Zoro’s bounty from EVERYTHING he does in Wano compares.