What if intelligence is real the same way that charisma is real?

Sure, some people have more or less of it than others, but at the end of the day, it's a poorly defined aggregate of personal characteristics that doesn't define one's worth or moral status and trying to put a number how much one has is a fundamentally wrongheaded way to think about it and will only lead you into paradoxes

(But in the case of intelligence, people keep trying to do it for reasons historically related to eugenics)