> Only a small fraction of healthcare spending should happen through insurance -- insurance should be for things where you travel in an ambulance to the hospital and that's it.

We already have that. It is called a high deductible health plan.

But health insurance companies do not just sell health insurance, they also sell price negotiation services, so you probably want to use them even before you hit your deductible/out of pocket maximum, otherwise you will end up paying more.