>>My mother - widowed during the depression with two sons- went to free clinics and we all somehow made it.

Religious hospital groups like St Vincent's still offer free clinics- funded out of other revenues. There aren't enough nuns let alone qualified nuns to provide the free care any more. So take away the other revenues and watch the free clinic closing and the facility sold for apartment blocks.

>>... And, barring extraordinary events (catastrophic insurance will kick in then) most people can pay for their care without any insurance.

Yes. While primary care is fully subsidized in the UK, in other places you might have to contribute $50 to see a GP plus a nominal $5 or so towards the cost of any medications. Kids generally are fully subsidized. Problem is that $50 is a lot of money for some families who might be forced to choose between electricity and a doctor visit- so you need to establish some sort of program to cover cost of care for those under a certain level. Medicaid, in other words. And secondary care is fully subsidized in most other jurisdictions, though non-urgent care also may be offered in a parallel private system where you'll have the same surgeon but a private room and a nicer menu. ;-)

The irony is that the US already has single payer care in many communities via Medicaid and after you hit 65, but it's the easily underwritten part in the middle creating all the ructions and costing a fortune.