(1) Going to college is in part a way to slow many people from entry to the job market. Not going to college is slowing to stopping. There are X-jobs and X+something people in the USA. College is in part a way to manage a too small job market. Students don't compete for jobs and graduate with debts such that they will take what they can get, not necessarily anything related to their degree.

(2) Since the 1971 Griggs vs Duke Power court decision, it is illegal to administer IQ tests in most job interviews. Education became a way to test for IQ by proxy. Combined with (1), this led to a feedback loop of more jobs asking for higher degrees to valve more applicants. What used to require a high school degree now required an AA, then a bachelors, then a maters, then a phd, not to filter the better people in but filter more of everyone out.