So Sanji's comparable to WHITEBEARD now??? The man did join Rocks, acquire a powerful crew, etc. To move up in his crew required strength, it wasn't about seniority or anything like that (as we saw with Ace becoming a division commander). In order to make sure he could always protect his sons he'd have to be incredibly powerful. There's no such deal with being a great cook or finding the All Blue. As far as we know nobody else strong is after it, and his philosophy is to feed anyone who's hungry so it's not like his dishes getting stolen is an issue.
We really don't know that Marco was always a doctor or is trained as one, I mean that very well could be a role he just took up due to his DF abilities having healing properties. WB did have a crew of nurses onboard looking after him at all times when he was older so it didn't seem as though Marco was classically trained or anything like Law and Chopper.
Big Mom argument makes no sense. She was naturally born absurdly powerful, Sanji was the opposite of that. She's actively aiming to become the Pirate King, and accomplishing her Totto Land dream absolutely requires strength. Nobody without strength and/or some other form of diplomatic authority can do so. Yet she acquired Totto Land by force, having stolen the land from a preexisting country, oppressively rules its citizens, terrifies crews and people from different races into submission, etc. None of this was achievable without her raw power.
I'm not a Zoro fanboy, if that's what you guys are gleaning from what I said. I have no bias either way. I like Sanji and Zoro about the same. Both great, badass characters in their own right. But Oda widening their strength gap (which was extremely small pre-TS) has been pretty blatant thus far. From having Sanji trained by Ivankov vs Zoro trained by Mihawk, to giving Zoro multiple complete 1v1 fights since the timeskip which Sanji hasn't had (his only proper fight against a halfway relevant opponent was a 2v1 with Jinbe against Wadatsumi), giving Zoro all those feats on the Rooftop, etc. We're in the final big stretch of the series. Zoro is headed directly towards being the World's Strongest Swordsman within the next few arcs. Sanji's headed towards finding that sea of dreams. Both grand, lofty dreams, but of entirely different natures.
People use King and Queen's relatively close bounties as evidence they're still close when everything else points to the contrary. The fact that King has constantly shat on Queen all arc long without nearly as much kickback from Queen as Sanji gives to Zoro typically. He also quite clearly functions effectively as a VC a lot of the time, which isn't really a thing in the SHs. And someone of King's caliber was the main antagonist of last arc, and his power was stressed heavily. So they're not really the same. Plus again, we really can't ignore the Rooftop. At this moment we don't know that Sanji's strong enough to damage a Yonko at all, let alone scar one. We don't know that he could've even held back Hakai for the millisecond that Zoro did. All these things add up. Oda's not such a shit writer that he'd just spring their dynamic back into place perfectly after all this, especially since it's been established that the SHs get stronger after every fight and that Haki gets stronger through fights as well.