Sure, but is that causal? For example, maybe there's some other factor (like SES) that's driving both. And switching to IQ tests doesn't really solve the problem, as your avenues for cheating on that are identical to LC.
You could probably screen candidates based on the question "Did any of your parents go to college? And if so, did they study or work in a STEM field?" and be roughly as predictable.
identical twins reared together vs apart, their IQs correlate more with their twin's than with the SES of the adoptive family.
high quality studies have found that the additive heritability of IQ is somewhere around 0.8-0.9, that's just totally incompatible with parental SES as the primary upstream cause. it's simply not debatable. and it wasn't debatable ten or twenty or fifty years ago either; it is one of the most well-established facts in human quantitative genetics.
ironically one of the things having a high IQ is bad for is having accurate beliefs about IQ; ask anyone who didn't go to college and odds are they'll correctly tell you that smartness runs in families.
Maybe IQ doesn't exactly track "intelligence", or whatever that is, but it is certainly tracking something that is correlated to success.