...You may believe a BS/MD program is squandering your college experience but I have plenty of friends who actually went through the program who would say differently....
Well, the folks who "went through the program" are poorly situated to know what they squandered. The folks I know who did BS-MD type programs, although many are good doctors, do not carry with them the same kind of experiences that the typical college grad does, and, whether they realize it or not, are worse off for it. They don't look back fondly on their college experience, didn't have that "coming of age" and growth experience many others did, and honestly many really don't have the same level of out-of-medicine balance and exposure that others do.
The European system where you go straight out of high school works fine for them -- they fix the glitches by throwing people out who don't cut it (attrition is very high in many foreign med schools). In the US, we instead opted for a system where folks broadened their horizons in college, gained maturity and experience, and proved themselves as superstars first, before acceptance. As a result, high attrition is not necessary. We chose this system over the European one, which predated ours, and I don't think many feel it was the wrong choice.
I agree that older people are not necessarily more mature, but statistically your odds of being more mature increase with each year you are on the planet. Most folks simply are wiser and make better decisions at 20 than 16, and our system embraces this. Which is why the combined BS-MD programs are falling out of favor, and there will continue to be fewer and fewer such paths until they become nonexistent in a decade.
As for becoming an attending earlier to make money earlier, I would again suggest that you give up a lot more than you get -- money received decades from now doesn't have much value in a net present value analysis, so whether you earn money at 28 or 30 or whatever is pretty meaningless, but investment in your personal growth in college in the near term is immeasurable. And even more important is having that extra few years to realize that maybe medicine isn't really for you -- allowing you to save time, debt, misery, etc. Bear in mind that earning a nice living is and always should be a very secondary goal -- the primary goal has to be to find something you enjoy doing, because you are going to be spending the bulk of your life doing it. And you only make good decisions by taking the time to think things through, to try other things, to broaden your focus. Folks who cut off the time to do this by funneling themselves into medicine earlier give up a lot of opportunities to figure out what they REALLY want to do in life. So they become doctors earlier, but that can really blow if you would have had a more enjoyable life being eg an urban planner. And how would you really know unless you spent time taking diverse classes and socializing with diverse people for a good deal of time.
The most important thing to remember is that 99.9999% of what you think you know about your life, yourself, what you want in a career, what you want in life, relationships, etc when you are IN HIGH SCHOOL is going to be wrong. Folks "mature" over time -- they make better decisions, prioritize differently (and usually better), and they know themselves better. So the person making a career decision at 20 does phenomenally better than the person who makes career decisions at 16. You may think you know what you are doing at 16, but you are an idiot -- we all were at 16. That you might end up in the same career if you chose later is irrelevant -- you would have made the 16 year old decision without all the facts, making it a poorly thought out and poorly reasoned decision. The nontrads tend to be best thought out -- they tried and explored other things first, and really spent the time coming to the decision, and as a result tend to be happier in medicine than most, on average. The trads are a mixed bag, with some having spent more time exploring other options than others. A lot of the whining and complaining you see in medicine tends to come from folks who jumped in with their eyes closed, and were upset when the reality didn't match up with their imagined career.
Medicine is truly not for everyone. So it behooves you (OP) to explore a lot of options before pulling the trigger. The is ESPECIALLY SO if your focus is to get out early and start practicing already, because this is a very very long path full of lifelong learning and tests, and if you are really focused on how quickly you can be done and earning, this is probably not the right career path for you, based on my experience. Physician incomes have taken a hit over the past decade, hours have gone up and we are almost guaranteed to continue that trend. In the decade it's going to take before anyone in high school becomes an attending level physician, it's very conceivable that the financial rewards will not be particularly impressive for physicians as compared to many other professional fields. So I would put financial reasons low on your list of reasons to become a doctor. You may rush through and find that you are earning a crummy salary as a physician at 28 rather than 30, when in either case you probably will watch your non-physician high school classmates earning tons of money doing careers which require far less education or hours. That's pretty common now, and likely to be more common in a decade as physicians are viewed by the government as unreasonably expensive. But I digress.