MD here.
First, if you are already thinking about your ‘side hustle’, then please don’t waste a spot in a US med school. There will be a huge shortage of MDs able to care for the aging US population in the next few decades. Leave that med school seat for someone who actually wants to dedicate their life to caring for patients.
Second, if your plan is to use an MD degree as a steppingstone to get rich, it’s a pretty dumb one. While med school will cost you hundred of thousands for tuition alone, the opportunity costs of 4 years of medical school + 3 (minimum, could be up to 6) years of residency + likely 3 years or more of subspecialty training are even worse.
(p.s: surgeons are also physicians)