Sorry I was re-using wording from the OP - did not mean to offend. My concern comes from the US having an extremely high cost structure unlike other countries that have successfully implemented single payer. If there isn't enough focus on reducing costs, a single payer system will require more aggressive means of financing.
I'm from the Netherlands. We have generally very good quality and affordable health care system, even though people on both the right and the left wing say otherwise. It's also very much focused on cost-reducation and whenever I read about health related costs in the US, I keep thinking it must be possible to do all of that for half the price. There just isn't the incentive to make care affordable. If you look at OECD reports (and those are fairly reliable) in the US, average health care cost per year per person are $9500. And you have to take account that a fairly big proportion of Americans don't have access to proper health care at all. In the Netherlands, that's about $5300 per person per year and everyone has access to good quality health care and that's fairly average for Europe.
What I find hard to understand about the US health care system is that there's a lot of economic freedom but costs don't seem to go down. That's absolutely contrary to what I was taught at school in economics, that competition and capitalism would lead to lower prices. It doesn't seem to at all.
Our health care system is paid through a combination of direct taxes, indirect taxes and premiums. Insurances are offered through private company, but the government decides a certain minimum 'basic' coverage. It includes basically all medication and everything that happens in a hospital. It doesn't cover dentistry, several types of elective surgery or contraception. There's a heavy competition for this insurance, it costs beteen €1200-1400 a year and there's a €400 co-pay a year. If you have a low income or are chronically ill, you can get a monthly benefit to compensate these costs up to €1000/year. Only adults pay, all health care for children is free. On top of that, you pay about 5% of your gross wages towards health care costs and your boss pays about 6% of your wages.
We have a wealth tax of 1,2% of your savings/investments over €50000, but the house you live in and pre-tax pension accounts are excluded. So yes, it's a little more difficult to FIRE in here. On the other hand, everyone has access to good quality health care and it's a lot more difficult to be truly poor in here. I'd say it's worth it.
I think when everyone has access to low cost, high quality health care, costs in the long term will probably decrease too, because people go to the doctor when they first start feeling unwell instead of waiting until they have heart attack.