Or a hybrid system with Medicare for all with income limits, above which you must either get third party insurance or pay a small tax is how it was done in Australia last time I was there. It seemed to work well when I was there, and I did have need of it. I had to go to the ER when I was peeing blood after being kicked by a horse directly in the kidney. Fortunately there were no blood clots and it passed after a day or two, but they had to do tests to verify it all and also an MRI I believe. I never got a bill.
I had more medical expenses from mandatory screening fees for visa applications there than from a potentially life threatening medical emergency. And it was included in my yearly taxes with no fees at the point of usage for anything I can remember offhand.
Meds were cheap because the whole country’s Medicare board bargains with the pharmaceutical companies directly, and if your meds are too expensive, they will just go with a competitor and leave that vendor out of the Medicare coverage schedule. This is not unequivocally a good thing, but those meds are still available on the market, but you will pay more for them unless you have third party coverage. Generics are also available just like most places.
Not sure if it’s changed since, as that was like 15 years ago.