College degrees used to be a signaling method. It was something rare and desirable. And like many rare and desirable things, the intrinsic value gets bolstered by a perceived value. The value and rarity drives commoditization, eventually making it not rare. (unless it can't or is too exepensive e.g. changing platinum to gold)
Everything has a mix of intrinsic and perceived value and this changes over time. The more a thing is composed of perceived value the more volatile it is. I'd say all stocks are composed of at least 50% perceived value.
Perceived value can often drag intrinsic value upwards so investing in things with high perceived value can still be lucrative. Analysis moves from fundamentals to psychohistory. (bad psychohistory) Probabky based on some combination of time to death of cultural momentum and half life of faith isotopes.
College degrees were a thing that quickly lost perceived value because it was based on rarity. (the only rarity that doesn't drive itself to commoditization is useless rarity like expensive wines and designer bags. 100% pure perceived value things not worth commoditixation)
At an individual level the high intrinsic value degrees do well but overall they haven't as most degrees in the US were supplementary for Masters of the Universe type. Education to fill the void in your life.
The post WW2 dominance faded though and the upper levels of Maslow's pyramid were no longer the issue. Basic survival and making a living was. Globalization also created huge pressure and competition for useful jobs.
What happened in the US was essentially a dearth of sinecure positions based on a secure moat that is now deteriorating. Those who are hit hardest by this desire a return to the past, in their eyes this is being "More American". They simply can't compete with a workforce with much stronger work ethics out of having much more experience with dealing with daily survival of a more extreme kind.
This is how the education system is failing. A country for abundance needs either output or the ability to extract rent via moats or force. The US also has a strong immigration culture that can "steal" output from other countries. Though at the cost of making "doing right by americans" a very loaded and confusing idea to parse.