That post wasn't directed at you, it was directed at the poster who is on probation. I have no idea why, I've certainly never reported him for anything (we have disagreed from time to time but he's generally pretty thoughtful in his posts and so I end up learning even when disagreeing).
As for what I'd do, it's pretty simple.
First, remove most care from insurance. Definitely primary care. Insurance shouldn't be used for things that are cheap. Your car insurance doesn't cover oil changes because they're cheap. Primary care can be very cheap as well if done right. When I had my solo practice, my patients paid $50/month for unlimited office visits. That's $600/year for unlimited family medicine care. Same thing with basic imaging. Cash pay radiology can be quite cheap. X-rays including read for $30. Ultrasounds for $100. Same with common labs. Lipid panels ran $7, CBC $5, pap with HPV $40, PSA $12. Removing all of that from insurance will decrease costs by a fair bit.
Second, emphasize primary care. We are a refer-happy system. That leads to duplication of care and extra costs that aren't needed. A good PCP with time to actually do good work can save lots of money, that's been shown time and again.
Third, decrease regulations. The US has way more non-clinical positions per physician than just about anyone else, that adds costs.
Fourth, let us say no. Every doctor has seen cases where care was given that shouldn't have been: feeding tubes for demented 90+ year olds, anything done for anencephalic patients, you get the idea. We spend way too much on futile care.
I can't say that would fix everything, but it would absolutely help.