Care is expensive because of insurance. Hospitals needs hundreds of administrators and billing specialists. Very little of that money goes to the doctor.
The difference between a rich doctor and a rich insurance exec is that the doctor helps people, and the insurance exec makes their money withholding necessary care from people, in effect torturing and killing them.
It's a tug of war, and even if insurance "loses", it doesn't matter, because you lost trillions of dollars in that tug of war. It's artificial inefficiency caused by privatization, very much a Dark Night burning a mountain of money situation.
https://www.npr.org/sections/health-shots/2019/10/22/7673763...
The fundamental problem here is that demand for healthcare is virtually infinite while supply is limited. Healthcare already consumes about 20% of the US economy and there is no excess capacity to expand it further without dragging everything else down. We can make some things more efficient and reduce administrative burdens but ultimately we have to draw the line somewhere and ration care. That's going to be true regardless of whether we have commercial insurers or socialized healthcare.