Oh yeah Doffy was quite above, but Sanji didn’t go alla out, and Sanji could likely dance more with Doffy before going down. Sanji tanked a 5 colors strings and can likely tank some more.
Doffy would beat Sanji 100% but parasite accelerated things by some margin.
Sure, that´s its purpose in the first place.
But Sanji´s DJ attacks is his second strongest, HM being his version of G4/Asura.
And DD took that laughingly, same way he dealt with G2, which means base DD was already above mid tiers.
Being parasited never spoke against Sanji since even a Y2C suffered the same fate, but everything surrounding it underlines he stood no chance, even if he could have tussled with him for a while.
And i personally think Sanji > G2/G3 lvl Luffy post-TS. Luffy had Elephant Gatling as huge AP move arguably, but most opponents would not get hit by it in the first place.