Not necessarily. Life expectancy for the urban population skews older but not dramatically. The difference in obesity is pretty dramatic with people living in rural areas being like 5% more likely to be obese.
I think some of that comes down to economics, some of it is diversity of healthcare and food options, some of it is just walking vs driving. A lot of things are just more walkable in the city.
Your doctor doesn't make an extra dollar off your prescriptions no matter how many drugs you take. I briefly worked in pharma, and it's not like in the 90s. The sales reps really can't get reimbursed for anything outside the pharma code. There's still stuff they can do with pharma companies, but it all has to be very above board. If anything they would probably be double dipping on insurance billable services like referring patients to a lab or surgical center they own for a second insurance check.
My experience both as a patient and looking at doctors I know personally is that they genuinely want to help their patients and genuinely care about improving people's quality of life. Plenty of them mess up, or fall short of that goal, or are so focused on doing more overall that they take a path of least resistance and patients fall through the cracks. But overall they're smart, decent, regular people who want to help.
Think about it this way, if you were a doctor would you push unneccessary drugs on people for money? Because if the answer is no, it's a safe assumption most others wouldn't either.