Ive been saying he never needed the boost. He just uses them.
What's the point of writing a growing dynamic character if you're never gonna showcase his growth or any struggle? It's even worse retrospectively because you realize Zoro has been strong enough to do something but just didn't because of... whatever?? What's the point of making him that strong if you're not gonna make him utilize it?
Zoro has never shown any struggle post timeskip other than gaining ACoC and being stalled by Lucci (who he didn't need a power up to beat and it was a pathetically drawn fight)
It's terrible writing for a dynamic character that should be taking Ls and GROWING but he's being treated like a Shanks or a Mihawk who have already reached their peaks