50 years of medical innovation leading to the propagation of procedures, medicines, and equipment costing upwards of tens of millions of dollars to procure and maintain.
Nobody is equipped to try to make an informed purchasing decision on if they want the $50k or $100k option to try to save their life while bleeding out of a gurney after getting hit by a car.
Oh yea, we're forgetting about the no insurance glory days of pre-WW1 medicine!
If your definition of "worked" is letting everybody die because most of modern medicine hadn't been invented yet, than sure, going back to those days would certainly drive down costs. No need for those expensive CT scan machines anymore, just rub some dirt on it.
The medical insurance industry is a free market. That's why it's such a disaster.
"Free markets" are certainly not free in any meaningful sense of the word. In practice they make no distinction between activities that provide customer value for a competitive price, and activities that are institutionalised economic extortion maintained by political lobbying and regulatory capture leveraged by plentiful access to capital.
The whole point of "free market" rhetoric in the US is to promote the latter while pretending to promote the former.
When I was a kid no one worried about hospital bankrupting the family. Now anything larger than a paper cut has the chance to bankrupt most families.
Combine that with the accident rate in cars you have an almost certain chance for a large percentage of the US to be bankrupt