Actually, many of those countries don’t have systems similar to Medicare for All. Netherlands, supposedly second in this list, has a mostly privatized system with mandatory insurance, so does Switzerland. France and Germany have semi-public and private health insurance companies. The US has bigger (and different) problems than merely the existence of health insurance companies.
The Wlz (which replaced the AWBZ) covers only a minority of total health care costs. Expenses were €29 bln in 2023. “Mostly privatized” is accurate.
Both the Netherlands and Switzerland have universal health care systems and negligible rates of lack of insurance. My point is just that private health insurance isn’t the (only) problem, as these counterexamples show.