UnitedHealth CEO shot

The difference is a for-profit healthcare system. The money to the stockholders has to come from somewhere
It's not just the money spent, it's what you get for your money. Denmark spends less but actually has better functional outcomes for its patients. In the USA you spend far more and get far less because there is no profit for enhancing quality of life, only quality of like eg kidney dialysis. The hospital where I work has a kidney dialysis unit and I can tell you not one of those patients is able to work, and they report a steady erosion of their quality of life.

There are situations where kidney dialysis can be warranted such as ARF, or acute renal failure, whereupon kidney function can be recovered. Using dialysis to extend life for chronic renal failure is quite literally painful, and only generates profit for the providers.