This is just a purely academic response to your question, but if you took me straight out of high school, and just dropped me into an apprenticeship-type situation in any medical field, I'm pretty confident I could come out just as competent had I gone through the classical college->residency gauntlet, and probably in a shorter amount of time. This of course assumes I have a minimum level of intelligence/work-ethic, a passion for medicine, and there were enough willing doctors going around to fulfill the demand for apprenticeships, but I think it's thusly theoretically possible to do away with college, although it would never happen.
US medical education is provably inefficient. You can take a sufficiently intelligent 17 year old and give them a top notch medical education in five years. In Ireland and the UK Medicine is an undergraduate degree and takes five or six years depending on the university. If you got rid of summers off you could do it very comfortably in four. Making medicine a second entry degree is a giant waste of social resources.
Wait, I thought the college was irrelevant? Why can't the brilliant 17 year old just read blog posts or whatever people who propose these positions think?
Anyway, I'm going to address a different issue. ... You really think you take a 17 year old straight out of high school level education and in four years they are a medical doctor? That's interesting ...
As much as someone just out of med school, yes. At an absolute bare minimum you still need to do your internship for a year before you can practice.
On your first point; most people don't use most of what they learn in college once they leave it. This is substantially less true of medicine than many other fields. At the same time most doctors do a pretty thorough job of forgetting math and physics and a reasonable job of forgetting chemistry.
Yeah because the majority of college students are going to study medicine.
When people talk about the "end" of higher education they mean an end to the thousands of psychology, communications, liberal arts type degrees. We will still have universities and phd's but not kids taking on thousands in debt so universities can build massive new building and sports arenas.
I don't think there is a better and we need to stop thinking in such polarized ways. People are different. Some people excel with formal direction, other excel on their own, and some people excel with all kinds of combinations in between.