Edit: the pre med prereqs are a good start. But I value the skills & concepts from the senior level bio/chem classes that I wouldn’t have gotten with a 6 yr track. Something also to be said for the emotional maturity that comes with 4 yrs prior to med school.
The salient question is cost/benefit. What is the cost in terms of lives and resources of those extra years? Do sufficient benefits obtain?
The US is globally known as a great place to get treated for cancers, especially. 5 year survival rates are relatively high - but of course only a fraction of Americans actually have access to the kind of diagnostics and treatments that deliver these outcomes, and only a smaller fraction of those with said access actually pass on significant assets to their heirs. For most, the medical- and death-industrial complex fulfills its primary extractive purpose.
I find it deeply ironic that your literally academic perspective ("Something also to be said for the emotional maturity that comes with 4 yrs prior to med school") is so utterly subjective - i.e. about your feelings, NOT data around outcomes. In the OECD, people live longer, on average, in places where less time and money is spent educating physicians. Yes, there are confounding factors - but this is true even controlling for the big ones like obesity
Not looking for proof of what you say (you say “impossible to prove” after all, and that’s fair) but surely something makes you believe this.
They aren't wasted but they're not necessary either, and I think that was the point. Let's say I wanted to become a general contractor, but for some reason that's a graduate program. I spend 4 years taking civil engineering. Did I waste my time learning about concrete... no, probably not, but it is necessary to do my job? Also no.
It's also hard to equate your "stronger early focus on STEM" with a pre-med program. If all it takes is teaching biology and math a little earlier, is that 4 years really the best use of time?