Even here in the UK - where we do have a socialist health care system there is still the option of going private. The only option you don't get if you are a normal tax payer is opting out of paying for the state funded healthcare - which is fine as far as I am concerned.
The US spends almost exactly the same proportion of GDP on public healthcare as the UK (~7.3%) but because the system is so horribly wasteful it gets much less for its money. (Much of healthcare spending is on the old who are covered by public Medicare because private insurance would be unaffordable.)
Not sure what that is supposed to demonstrate - it's hardly comparing like with like to compare the UK with the "free at the point of delivery" NHS available to everyone with a system where:
"This has led many households to incur Catastrophic Health Expenditure (CHE) which can be defined as health expenditure that threats a household's capacity to maintain a basic standard of living.[2] As per a study, over 35% of poor Indian households incur CHE which reflects the detrimental state in which Indian health care system is at the moment"
In fact, if anything, that perhaps reminds me of the pre-NHS UK healthcare system - which Aneurin Bevan, the founder of the NHS, clearly referenced in the title of his book "In Place of Fear".