It used to be that low NHS standards, still just about the worst in the world according to EU and British Medical Journal studies, were somewhat compensated for by the fact that it was at least relatively cheap. These days we spend over the OECD average on healthcare while still getting poor results. The NHS has gone from cheap and nasty to just nasty.
This year the NHS budget is £104 billion, over £4,000 per household. Despite that massive subsidy from taxpayers the NHS often charges more for basic dental treatment than many private providers. People who buy private healthcare pay twice for provision - taxes to pay for the NHS and private insurance premiums or fees to pay for their own coverage. Only the incompetence of political management could make paying both taxes to pay for the NHS and private treatment costs cheaper than using the services NHS spending is supposed to provide.