Pretty much all that needs to be said, some people can try and wiggle around it but when its all said and done the upper echelon of the Straw Hats, especially Luffy/Zoro are going to surpass alot of past figures not only because the narrative demands it for obvious reasons but because thats just how most Shonen end, with the MCs ending up at the top of their respective verses, we've seen it with Naruto, Bleach, etc. One Piece is not different in this regard
Zoro doesn't give a flying fuck about Roger. He doesn't even give a shit about surpassing Ryuuma. All Zoro cares about is being WSS, and that means surpassing Mihawk.
However.
This is a shounen. Zoro will be the strongest swordsman to have ever lived. Why do we know this? Because he's been consistently paralleled with Ryuuma, a man hyped as the sword god. Therefore, by performing feats nobody has done, Zoro will be hyped as the new sword god.
Guess what? Luffy doesn't give a flying fuck about Roger either. But this is a shounen and we know that Luffy will surpass him by achieving what Roger never could. The two are related through parallels. Roger has absolutely nothing to do with Zoro. Ryuuma represents Zoro's Roger. Whether Zoro surpasses Roger or not depends on how strong Ryuuma was. That's all there is to it.
However.
This is a shounen. Zoro will be the strongest swordsman to have ever lived. Why do we know this? Because he's been consistently paralleled with Ryuuma, a man hyped as the sword god. Therefore, by performing feats nobody has done, Zoro will be hyped as the new sword god.
Guess what? Luffy doesn't give a flying fuck about Roger either. But this is a shounen and we know that Luffy will surpass him by achieving what Roger never could. The two are related through parallels. Roger has absolutely nothing to do with Zoro. Ryuuma represents Zoro's Roger. Whether Zoro surpasses Roger or not depends on how strong Ryuuma was. That's all there is to it.

