American doesn't have a "system", that would imply centralized management.
Instead we have a dozen or so smaller "systems" most private but a few public, all operating to varying degree's of success. The worse by far is Medicare, second is probably Tricare, after that it's about how much money someone has.
The USA has the highest quality of healthcare in the world, that quality comes at an astronomical price tag. Furthermore the entire health costing system is hidden behind a barrier of *** numbers. Like on paper they say $10,000 for a procedure, in reality they only charge %5,000, unless it's to medicare then they charge higher. The way medicare pays, it's a percentage of billed price "within reasonable norms", meaning the average of the providers who accept medicare. If they all agree to charge around $10,000 for the procedure, then medicare will pay the percentage of that, while folks with insurance pay less.
"Medicare for all" will just jack up our health costs into the truly obscene because it fails to address the root cause of the issue, and that's costing.
See the USA is subsidizing the worlds pharmaceuticals, their all developed here and make most of their money in the US market. They then sell to other nations for those socialized prices because it's extra revenue outside of their cost recuperation model. Should the US suddenly clamp down on prices, the manufacturers would either cease researching newer drugs or severely restrict what they do research. Nine out of ten experimental drugs fail testing, half do so after they pass initial animal trials. That is a ton of sunk costs that tenth drug has to cover for. Furthermore, due to our tort system and healthcare regulations, there is no low cost option available. It's either door side limousine service or driving a moped.
That last one is something me and my wife talk about all the time. See she's from South Korea which has a health model that's very different from the gold plated Gucci one we have or the obnoxious one that European countries have. There the government doesn't tell healthcare providers what they can charge, only what the government will pay for something like 80% of common procedures. While also relaxing the requirements on how providers can run their clinics. And by relaxing I don't mean sanitation, but they don't have stupid ***like "admitting privileges" or required to have ten different specialists on call 24/7.
The cities have a handful of really big University Hospitals, outside of that it's a bunch of smaller "hospitals" that we would call urgent care clinics. Some are equipped with an OR or other high end facility, but most aren't. Believe it or not but this takes care of most needs at a reasonable cost to the population. It keeps costs low and gets care to the general population at costs they can afford, not pretty but practical. As for doctors, well plenty of those and they don't make near the amount of US ones, at least not in their first years. They also don't have mountains of student debt piled on that they have to work through.
Anyhow, the issues with the US is more about over regulation coupled with very shady pricing tactics. At current prices, "medicare for all" ends up a giant wealth redistribution from middle class Americans to the liberal elites. Rich people won't pay anymore in taxes, all their money is already safeguarded in capital investments. After all you liberals still think wages are an actual source of wealth.