Who's making all the money? Drug companies? Hospitals? Health insurance? Doctors or nurses?
Yes.
Yes.
edit: forgot a "slower than"
That said, a masters in nursing isn't easy, a good nurse earns their pay.
https://www.bls.gov/oes/current/oes291141.htm
The majority of nurses are RNs and make well above median wages. LPNs still make better than average money.
They aren't getting incredibly wealthy, sure, but they aren't working for peanuts either.
It's anyway probably not a great argument if you are trying to make people making 5-10x the median wage some kind of baseline.
Sure nurses and Doctors make money but if you know anything about that job any good one is probably underpaid.