The United States already has the most expensive health care system in the workd. But it is by no means the best. Most countries in western Europe have better health care systems, at less cost.
On a scale of 100, being those of U.S. levels, Westerrn Europe's costs are something like 77. But it would cost most countries something 53 to deliver the same level of care as in the U.S.
Let's start with the cost side first. About 10 units of this cost have to do with "defensive" medicine; that is medical (and paperwork) procedures that are basically unnecessary, except for defense against malpractice suits. The trial bar is a non-factor in Europe. America has 5% of the world's population, and 95% of the lawsuits.A second factor that costs about 10%, is fraud in dealing with claims, usually Medicare or Medicaid. Take these two factors away, and you have U.S. health care at roughly western European cost levels.
The second question, then, is why the quality of health care is better in Western Europe than in the U.S. after equalizing cost. The reason is that "medical doctor" is now a much more honored profession in Europe (and Asia) than in America, where litigation (and the occasional gory story of genuine malpractice) has tarnished the image of the profession. America's 'best and brightest" do not go into health care. Many medical school slots are occupied by "wannabees," albeit of above-average, but not superior, intelligence. (And a lot of (naturalized) "American doctors are actually foreign born. Instead, America's "best and brightest go to Wall St., and become derivatives traders.