Luffy went from Marco/King to Old Rayleigh or Fujitora level, not Cracker to Big Mom. That's fucking dumb. He was Y1C in WCI. People have got to stop wanking YCs. Cracker was beaten as a joke. There was no way he was Luffy's level. He just had a good counter.
Luffy could break out of parasite in Dressrosa. Jozu, a "YC2", couldn't. There really is nothing special about YC2s that Sanji can't achieve. Even if he beats Queen, he's getting raped by Doffy in Dressrosa, just like Jozu/Law, and is still below Dressrosa Luffy.