I certainly understand the economic point you are making but I don’t believe that money is at the heart of the problem.
My plumber makes $100,000. He can’t find apprentices. My local community college has dropped their plumbing certification—no interest.
As a society we “crossed a bridge” some time ago. College has been established as the norm—a rite of passage. It doesn’t matter whether or not Little Joanie is all that “book smart.” By golly, she’s going to college. (It also doesn’t matter whether or not she has to enter into indentured servitude.)
The high schools are of no help. They have gutted their vocational training programs. Many high schools don’t even acknowledge the existence of these vocational opportunities because they are so busy channeling their students into four-year colleges to meet government imposed “college readiness” standards that make absolutely no sense.

Thomas B Walsh’s answer to https://www.quora.com/Why-does-it-seem-like-high-schools-in-the-U-S-dont-even-bother-telling-students-that-they-can-go-into-the-trades-and-make-a-great-living-They-make-it-seem-like-college-is-the-only-path-to-success-Why-not-get-paid-to/answer/Thomas-B-Walsh

Nobody wants to get their hands dirty. These types of jobs have been stigmatized, but there is more to it than that.
“Not going to college” has been stigmatized in segments of our society.
If you don’t go to college, many people are going to think you are dumb and lazy.
Here are some examples of jobs that don’t require a four-year degree, but, pay “breadwinner” salaries.
I used my plumber as an example of trades. Yes, there is a physical aspect to that job that is going to become a lot more challenging as the guy gets older. However, there are Blue Collar Baby Boomers retiring every day by the thousands who worked these kinds of jobs for forty-five years. I wonder what has changed in our society?
I know of an office job (Certified Ophthalmic Medical Technologist) that pays $71,000. It requires several levels of certification. The employer would provide the training on-the-job, i.e. you get paid to learn. That is, if the employer could find anyone to hire. All the potential candidates are in college majoring in something like Puppeteering.
My local community college has a robotics program. It takes two certifications, i.e. a two-year associate’s degree. Some of the classes are free—government grants. Upon graduation you become a candidate for a full-time job paying $25/hour with health benefits and a tuition benefit. There is some minor manual labor, but it is more programming than anything. You could “eat off the floor” of these manufacturing facilities. (You can travel internationally, if that is your desire.) Almost no takers.
There is a community college, Gateway, in Northern Kentucky with a multi-million-dollar mechatronics program. Very little interest.
Monday evening I attended the “swearing in” ceremony for four new police officers for my community. This job comes with a health benefit, tuition benefit, and a very nice pension plan. After their training period their salary is in the “breadwinner” category. Our small city has a very difficult time finding candidates who can meet the requirements.
Gold and platinum smith. No interest. Thanks to https://www.quora.com/profile/Jo-Haemer
Notes:
Read Charles Murray’s, Real Education, 2008. His thesis was that too many young people, many academically marginal, opt for college.
My point is that while the less academically gifted may end up graduating with some degree or other, when it comes to competing for the well-paying professional jobs, they are going to get their butts kicked. On the other hand, they could have taken a different path, sidestepped their adversaries, avoided student loans, learned a marketable skill and become gainfully employed.