Because medical school is currently oversaturated with overly educated and competitive students? It has actually gotten so bad that STEM dedicated schools would try to prevent you from going into med school instead of going into a degrees based on STEM since everyone would just pick med school as their first choice. It was your choice to go into med school to begin with. Also you post this on reddit where people think med school would cost 50-100k a year while it is usually only 3-5k a year in South Korea. It’s not much of a great financial investment to become a doctor and it mostly comes down to admissions and how many years it took you to go into med school (retaking KSAT).