There's going to be public and private sectors no matter which party is in control.
The private sector is perfectly appropriate for providing goods and services that people acquire through discretionary spending---
as long as it's regulated enough to provide reasonable protection to workers, consumers, and investors.
For necessities like health care, just to site one example, the private sector is a waste. Money that should go to the actual health care services is instead wasted on huge insurance company profits. Do you think it would be that hard tom develop a safe appetite suppressant for obese people? Of course not, but no development goes into that because illnesses arising from obesity are so profitable to pharma, to insurance, and even to physicians alike. That's just one small example how socialized medicine makes more sense.
There are plenty of appetite suppressing agents (you can even do it with accupuncture). The issue is you cannot make people use them.
What are insurance sector companies usual profit margins? The insurance industry's net margin in 2017 ranged between 3 and 10.5%. Life insurance had the widest range between quarters, from 3% to 9.6%; property and casualty insurance were at 3% to 8%; and health insurance had the narrowest range of 4% to 5.25%.May 7, 2018
Hardly huge.