I had brunch with a few young doctors in fellowship yesterday. Depending on the field, they are expecting to start at $400 - 700k / year (private practice). Expecting to be well over that in a few years. These students are from good, but definitely not top med schools. Dermatology / plastic surgery seems to be the most lucrative specialty. Many expect to be earning over $1M / year eventually. One person said they knew of a guy who made $1.7M last year, but had to do a ton of overtime to get that. Long story short, in terms of maximum profit potential, finance wins, no doubt. But if you are willing to work hard, maybe medicine / tech offer a higher probability of achieving a high salary. Not every junior banker at Goldman will become a partner. But most people who make it into med school (not easy or given in itself), will become a doctor and many specializations in medicine pay very well.
That said, with medicine, it usually involves a ton of debt and the high salary usually does not come until one is somewhere in their 30s. It's also highly risky. Not uncommon to have 30 hour shifts, many don't make it into med school, and there's some malpractice risk. So the high salaries come for a reason. I had not really considered medicine the best path to pursue if one really wanted to make a lot of money given hard work combined with intelligent application, but these young doctors sure seemed interested in money and I got the impression, that might have been their main motivation for becoming a doctor. Btw, doctors actually do talk and joke about their some of their patients / extreme cases outside of work.