Your comment actually presents an idea that many choose to ignore, that healthcare is actually two markets in one.

For routine primary care like regular checkups or an appointment for some symptom bothering you, you absolutely are not under duress. You won't die because you took 5 minutes to choose a doctor on ZocDoc. With more transparency in costs of service, this could definitely become a market, ie "for $XX per month, get unlimited visits to our partner doctors' offices".

For emergency situations, surgeries, and things that require expensive ongoing care like cancer, you're correct in that you're under duress and can't really shop around. This is the market in which the usage of insurance makes sense, as it's a rare occurrence that would be catastrophic to pay for out of pocket for the majority of people.

I think we can do a great deal to lower cost of healthcare to Americans if we think of it in this two market approach, and handle each accordingly.