lot of potential flaws no?. kizaru also possibly the main antagonist for this arc and that comparatively puts him in a bigger spotlight plotwise.
It’s often the case especially in stories like shonen
Obviously it’s not 100% bulletproof but I feel it often works like that
And yeah if Kizaru is pulling a Katakuri (huge 1 vs 1) fight with Luffy then we can talk
But even with that it’s without knowing how great Kuzan presence will be in the end of the manga. Kuzan still has plot points : he is a commander under BB now, he just fought Garp and he will obviously have more panel time after with his possible downfall.
Kizaru can be as great as he can I think his road and relevance stop now. Kuzan shadow over the story is I think bigger than Kizaru’s