Law school may be a very apt analogy. I remember the doctors in my family and family friends who were doctors always told me to go to law school because "lawyers make more for less work." Which I suppose is true, but there's more to even the dreaded med mal lawyers than just showing up in court with a legal pad. I think with law the ceiling is higher, the educational investment is less, but the rewards are not as evenly distributed. Yeah, you can make 160k straight out of law school (3 years, as opposed to a primary care doctor who needs 4 years of med school and what, is it 3 years for internal medicine?). Add to that, there are no prereqs for law school. All you need is a high GPA and high LSAT (for the top schools, these days you can have a crap LSAT and get into lower tier law schools). Good ECs are a big plus, but I know plenty of people who got into great law schools without any kind of legal shadowing or volunteer work or research-the barriers to entry are almost nonexistent.
Problem is, those 160k BigLaw jobs are not available to the vast, overwhelming majority of graduates. Now, I'm not a doctor and I'm not knowledgeable about healthcare economics, but I'm willing to bet that the vast majorities of internists can get a decent job somewhere. At pay that a lot of premeds look down their nose at, but nothing horrible.
So I would say law is much higher risk. You can come out 4+ years ahead and start making money right away-but there are not enough BigLaw or even mid law jobs to go around (the ABA could take some lessons from the medical community, they're really asleep at the switch when it comes to saturation of lawyers). If you get one? Those jobs aren't forever. Something like 1 in 8 people (if that) will make partner. If you make partner at a cream of the crop firm, you can clear $1 million a year. The best plaintiff's attorneys can also make millions. But they are the outliers. I think close to 50% of legal graduates can't find legal jobs, and those that can, it's closer to the mid 5 figures-which is not terrible until you take debt into account.
And the other problem with legal education is that no one comes out of law school ready to practice law (trust me on this one, I'm an attorney). No matter how many clinics you've taken. Again, I'm not a doctor, so I'm sure that doctors fresh out of residency feel unready, but at least they have years after school dedicated to training. Law you either get a job at a place that trains you (albeit in a much less formalized way) or you learn on your own. So if you're coming out of law school today from a non top 6ish school (even graduates not highly ranked in their class at the lower end of the T14 are struggling) you have almost even odds of not getting a job, *and* you have no real training so you can hang a shingle but you're really up **** creek in the preparedness department.