Zoro gets destroyed by any admiral or yonko 1v1 and is much more comparable to Sanji than Luffy.
Zoro does have ACoC and hence can compete with top tiers in terms of AP(even that, on to an extent). But he cannot compete with top tier speeds or FS.
Sanji on the other hand has much better speed and CoO than Zoro, meaning even if he can’t match Zoro’s AP, in a 1v1, Zoro would still have considerable difficulty as he’d have a hard time tagging Sanji.