nobody gives a fuck. no serious mathematician has ever taken an IQ test. no serious mathematician would take seriously a 1-dimensional measure like IQ to be predictive of high dimensional things like intelligence or even success
Psychometricians searched for decades for any positive outcome not correlated with IQ, without success.
The g factor obtained through factor analysis captures the most sought after aspects of intelligence. Read Human Cognitive Abilities by Caroll. The only reason to ignore this is that you are hoping that you are smarter than you are. Maybe you don't want a regression to predict that your chance of winning the FM is below .1%, which can be hard to swallow.