You:
Zoro can't low-diff Lucci because he struggled all this time and only won because Sanji motivated him.
Reality:
Zoro finally got serious and casually one-shotted Lucci.
The 'reality' is manga fact. And yet, you are claiming that Zoro cannot casually defeat Lucci as he has just shown, because he has low end feats which show him clashing evenly with Lucci. You're disregarding Zoro's high end feats and judging him based on his low end feats.
Well, if we're powerscaling characters by their low end feats, we get Mihawk ~ Vista. We get Base Zoro > G5 Luffy. We get Fujitora >= Dressrosa G2/3 Luffy. We get foolishness.
Base Zoro could've ended the fight vs Lucci at any time. He even said that outright lmfao. But what Zoro did in this chapter is a top-tier feat that only Shanks and Kaido have replicated, and this contradicts your powerscale. So you're desperately coping and digging yourself an even bigger hole.