The majority of healthcare spending goes toward treating patients with chronic conditions primarily caused by lifestyle factors such as overeating, lack of exercise, and substance abuse. There is effectively infinite demand for healthcare services in that population. Depending on how you count, something like 1/7 of all healthcare dollars go to type-2 diabetes and related conditions alone.

There is certainly some inefficiency in the US healthcare system but mostly it reflects the poor health of the population. Switching to some form of socialized medicine won't fix that problem. Other developed countries are doing a little better at the moment but they're on the same trend line and will inevitably hit the same crisis. At some point if we want to prevent a systemic collapse we're going to have to get serious about emphasizing prevention over treatment.