>IQ has a lot of flaws, not the least of which is its usage outside of academic research, as a measure of job aptitude and hiring potential
Isn't IQ one of the best predictors of job training success, across both civilian and military, blue collar and white collar?
It's also one of, if not the single most generalizable predictors that we know of right now, even more so than nationality, race, gender, SES (socioeconomic status), parental SES, you name it. It predicts just about everything - from hard biological measures like reaction time and brain mass to lifetime odds of being in a car accident (distinct from causing a car accident - higher IQ people are statistically less likely to be hit by another driver), divorce rates, lifetime income, longevity, the list goes on and on. IQ is not the strongest predictor for every one of these, but every stronger predictor for any one of those fails to predict as many things as IQ does. Parental SES, controlling for IQ, provides no predictive power for your reaction time, for instance, despite predicting educational attainment better than IQ does.
The critique that IQ is an imperfect proxy for g is totally valid.
The self-assuaging fantasy that g itself doesn't exist is a classic example of a psychological defensive mechanism of rejection, one rooted in a need to defend a worldview that holds all people as inherently equal, when we're measurably, biologically not.