6/10
I mean, he was successful enough to usurp Wano for 20 years, turn it into factory of smiles, he had influence over other strong pirate crews, kept his Yonko title before Luffy dethroned him, which is by OP standards quite good. Power-wise, he was formidable enough to be a post-TS villain, although I hated the final moments of his fight with Luffy, mostly because of Nika tunes.
But, his personality fell flat to me, his motivations were not really explored properly, he was looking for a JB for what? Even BM, as laughable she was handled, had a better characterization overall, she had a goal of getting power and uniting all races under her rule, tbh if she had a better mentor by her side I could totally see BM being in a good side rather than bad.
So looking back, Kaido didn't live up to his hype, but objectively he was a force to be reckoned with, and Wano finally getting free from his rule is a big deal in OP verse.