Isn't this obvious and also arguing against only a straw-man position with respect to intelligence and intellectual skill -- namely that intellectual skill is a function of one variable (intelligence) and that all other factors (such as industriousness & creativity) have no impact on intellectual skill?

It's phrased as if it conveys some deep wisdom, when the reality is that almost all reasonably intelligent people already believe this.

Reminds me of the Geography teacher I had with cerebral palsy, compared to college kids with no aspirations beyond working a coffee shop.