This is a crock, matter of fact it is better if you don't have a higher IQ as you will have a tougher way of life dealing with other people and often lack patience. I can't name one billionaire who made their wealth without dealing with people.
https://researchnews.osu.edu/archive/intlwlth.htm
Higher IQ does mean they tend to earn more money, but earning more does not necessary become wealthy, they more dedicated and focused, but often times wealthy people look at the forest and less so on each tree.