I don’t agree. My kids have all gone to schools where their stats have been significantly higher than the avg admit. They have all excelled and thrived. They work with their professors. They are recognized as top students and they are mentored as such.
They have chosen self-selecting majors, though. ChemE, physics/math/EE, and Allied Health. Probably most of the students in those majors have higher stats than the avg admit. When you are talking about large publics, thousands of kids make up the avg stats. A given dept may have 30 students/yr in a specific major.
My husband was one of 15 chemE students graduating when he earned his degree. ~4000 students graduated. What was going on the chemE dept did not match the sociology dept. That is going to be true at the majority of schools.