IQ is limited because it only looks at one facet and it generalizes a lot. Tests that look both into ability and aptitude, and especially those who split them by domain are much more relevant and applicable to real world scenarios.

IQ does actually measure quite widely, but only one of many parts (the visual pattern matching part) is widely know outside of academic use. But even then it should not be used for hiring or intelligence scoring people against one-another.

If you actually want to test people for hiring, using domain specific interview questions and tests is a-lot more reasonable and usefully correlated with real-world job performance.