People need to realize is that Yamato's whole character arc here is about NOT being shackled down. Her devil fruit being regarded as "The Guardian Deity of Wano" should further enforce the notion that she will leave the Country. Whether it be as a Straw Hat, or by some other means, she is leaving Wano. This is the same thing Oden went through being born as the Shoguns son, and the fact that the borders of Wano were supposed to be closed. He didn't want to be shackled down either, and chose to follow his own path. That is what Yamato is trying to achieve herself.
"If Sanji was that guy?" What guy? "Wings of the Pirate King?" He literally is. This is a stupid argument where you're trying to argue a fact.
If you cannot understand it, you are literally Black Maria. That's you. Next chapter Robin will beat you and move on.
You have built an argument based on deliberately misunderstanding what Oda wants to do with Sanji and ignored his narrative choices.
Sanji has always been "that guy." And you cannot ear your cake and have it, if you want to bring up bounty (which is 100% the only meaning of Supernova), then Sanji's bounty is >= Zoro, so what're you talking about?