Non of those are "hard fights". What Zoro said takes into account the context. In every island / almost every arc prior to EL, Zoro and co had extreme diff matches / close death occurrences. Sanji has had non yet you claim he goes from Not doing Anything to Doffy to being above him because he Damaged Queen
It don't need always to have hard battles.
The strawhats monstertrio learn complete new skills during a 2h train. Luffy master his Adv CoA in Udon without hard battles, just by training.
Sanji have 2month of time to became stronger. During that time he face the big mom pirates right after facing Doffy.
He fight Judge in a hard battle. He fight overall in Wci arc, he fight a veteran multiple times,he one shot a strong minister. He had so many experince and clashes. Luffy just get in 2days already stronger in Udon via training,before he try to learn adv CoA.
Sanji had same time as Luffy and Zoro,saying he didn't train? Improve after all the events is a dumb though.
Current Sanji should at least been one-two leagues above his DR version. Like Luffy improve and been 3-4 league above his previous DR Version.
Alone the fact that Sanji need now G4 power alone just by fighting a YC shows enough. WCi Luffy who was> DR Luffy need his G4 to fight back YC.
We talk about a dude with a bounty of 1.3B,a guy who Marco and Luffy himself even hype.
Doffy is the guy who could get matched by Base/G2 Luffy in physical aspect as
@ODIAK D.TSEGNORTS pointed out, Wci Luffy in Base/G2/G3 get stomped by Cracker very fast, only with G4 Luffy was able to fight back.
And we speak about Queen who is most like>Cracker and Sanji match him.
You are delusion if you think that Sanji didn't get stronger since DR.