Luffy is the most privileged by far
Then Zoro. Both also have CoC, the chosen ones ability, literally.
Sanji is the least privileged.
People forget Sanji would be basically equal to his brothers if had born as the Stealth Black, another mere copy of his brothers. How is that a good thing?
Most of the potential he has now is only possible because of his own strength, training and decision making. Otherwise his brothers should be just as strong as he is, or far stronger, which was never a thing already in WCI.
Oda literally needed to give Queen Germa powers and make Sanji destroy his suit, then make Sanji use the suit's ability without the actual suit, to show us how much build different he is.
A few minutes with the Exoskeleton and Sanji already learned more and did more than his brothers in decades. Not to mention that there is a long long way until Sanji awaken those powers, and i certainly wouldn't call it a privilege.
Meanwhile Zoro: Almost a clone of Ryuma, descends from Ryuma, identical in every aspect without any further explanation. Gets swords that helps him train and get stronger, without any actual real challenge or great effort made (only Enma pushed him to such situation), those swords are all tied with the Shimotsuki. Just compare those with the path Sanji needed to go through to get his Raid Suit until the moment he awakened the "science" in his body, it's apples and oranges.
Also Luffy trained with Rayleigh, Zoro trained with Mihawk aka WSS, Sanji fought a never ending army of Okama led by Ivankov, learned Haki and a few special recipes from Ivankov.
If Sanji gets Conqueror's then i would say he is more privileged than Zoro, but it's basically matched. Oda is still cooking something with Sanji, so things could change in the future depending on how this is handled.
But overall Luffy is the most privileged by far, there is just too much things going for him, everything around him seems to be special.