Supply and demand. It's no surprise that when we had 10% of people going to university in the 1960's and now we have over 38.8% [1] that the economic value of a degree seems to be getting watered down.
No different than any other form of inflation from the government blowing on the fire (subsidizing with money) without adding any actual fuel (intrinsic value). Just like housing and healthcare.
[1] https://educationdata.org/education-attainment-statistics#:~...