Jordan Peterson always says that, when it comes to predicting success in life, IQ has the highest predictive value of all the traits that we can currently measure.
https://en.wikipedia.org/wiki/Kim_Ung-yong
The other problem being that "high IQ explains everything" people don't actually go around personally going around giving people IQ tests. They just read somewhere that X guy has IQ Y and then decide that's evidence for something.