Med school is a lot of work but the time commitment is grossly exaggerated, I suspect because the majority of med students have never held a real full-time job and it's more than anything they're used to in undergrad. It's a 45-50 hour per week commitment, on average, for someone of average learning capabilities (by med school standards) during M1 and M2.
Studying for 9 hours a day is certainly more mentally taxing than say, a job as an accountant, but the hours per week required to be successful is not any different than your typical full-time job. Most people wouldn't recommend working an additional job on top of a full-time job, but there are certainly people that do it. It just requires good time management skills.