It’s even more obvious with high school degrees. Most people cross that threshold, so the people who didn’t now represent a usual group of under achievers. The threshold is far below what FAANG’s are looking for, but requiring a HS/collage degree can effectively presort applicants for jobs with lower thresholds.
Unfortunately, such methods consistently exclude many worthwhile applicants from a wide range of jobs the same way asking for a criminal background check. But that then sets up a stronger feedback loop as people have stronger incentives to cross that threshold.