Jackiest
If you think the price of private health care is expensive now you wait till there is no NHS and we have no option but to go private.
Private healthcare is expensive, but few people use it. Most of what people say is private care is just paying an NHS-trained consultant working privately in an NHS hospital for a one-off consultation and then jumping back to NHS care, so is not 'going private' at all. That costs a couple of hundred pounds (plus tests in some case), so is affordable for many but lengthens the NHS queues for those who don't have that money spare. It is the operations that these patients then get on the NHS that are expensive. If there were no NHS this would not be an option.
I can't imagine a fully private health system, as people would soon find that they would have to sell their houses or declare bankruptcy because of accident or illness. It isn't just the operations that would contribute to that, but the hospital care (which would no longer be available on the NHS) and the medication that a lot of older take routinely already, plus painkillers and other post-operative drugs.
If NHS treatment moved to insurance-based scheme, the chances are that most of us on here would struggle to pay the premiums, as existing conditions and advancing age will make them prohibitive. Younger people will be justified in saying that they should be able to opt out of paying towards what is now the NHS, so there will be even less to fund those who are not insured.
Sometimes people suggest that the ill-defined 'those who can afford it' should pay for what others get free, but they never pin that down to explain what 'can afford it' means. If that happened, unless 'those who can afford it' included so few people as to make it all pointless, there would be no point in anyone saving for old age or talking out private pensions, as doing so could tip people into the category whose life savings would be wiped out if they needed an operation or life-saving but expensive drugs.
If fewer people had savings or private pensions, it would mean more people claiming pension credit, which would take money out of the general welfare budget, and potentially would also mean that people would have to sell their houses as they do for care. There would also be less money circulating in local economies if fewer older people were spending 'the grey pound' on coffee with friends or other retirement pursuits.
Assuming that people sold their homes to pay for operations, would they be expected to cover the whole cost of healthcare, or a proportion? If the former, would there be a way to ensure that those living in areas with low house price inflation wouldn't get lower levels of care? Would the system suggested for care homes (ie that there is a cap that represents a tiny amount of the average price of a house in the SE, but most of the cost of a house in some areas of the North) be brought in, even though this would further increase geographical unfairness and kill the idea of so-called 'levelling up'?
There is already resentment at the two-tier care system, but it it would be political suicide to extend it to healthcare too.
(Sorry, Mawmac for derailing your thread further, but I often think that people who make these simplistic suggestions haven't thought them through.)