That is a HIGHLY antiquated narrative.
One, it was published and marketed by the institutions it supports. That is what you call a conflict of interest.
It fails to stratify by trades.
I have three adult children. One is a Lawyer, One graduated from a semi-Ivy league school with a STEM degree, the youngest said to hell with college and went to lineman school. In his first year the Lineman's Gross Income will be more than the other two combined.
NO … The false narrative the college grads make more than non-college grads is a complete fallacy.