Even in those countries, you are giving up four years of wages. The only reason any ordinary person does that is because they expect to get something out of it beyond mere life enrichment.
I'm listening to music without any expectation of profit, giving up time I could spend making money. I consider this life enrichment. Actually, besides opportunity costs, I paid literal cash money to be able to do this.
That is, the problem isn't that "enrichment is bad", or that everything must have a monetary return, but that "it's not a high enough priority at that point in the typical such person's life to spend that much on it" if it were just an issue of enrichment.
It's like the Burdian's Ass scenario, except the donkey starves while learning the most enlightened way to choose a bale of hay to eat.
The music analogy you tried makes no sense to me. You cannot work 24/7. You are not in any reasonable sense forgoing wages you could have earned by listening to music. If you quit your job to listen to music eight hours a day for four years, I would argue that you are either a fool or very wealthy, and I don't think I'd find many to disagree with me.
The government subsidizes retirement in a plethora of ways.
The "enrichment" model isn't premised on "job training doesn't matter". It's premised on the realization that it's impossible to know what you don't know but might need to know for a job that you'll have in 2 decades but doesn't exist yet.
Examples abound of Mathematics majors who make tremendous contributions to industries they never studied formally. Many people who never obtain a deep theoretical knowledge of a field do well in life because the usefulness their industry knowledge just happens to outlive them.