We do have single-payer healthcare for all NHS services. You cannot pay for NHS services, and NHS services will cover almost everything you'll ever need so long

We do have single-payer healthcare for all NHS services. You cannot pay for NHS services, and NHS services will cover almost everything you'll ever need so long as the treatment is actually proven to work - it's a newspaper-worthy situation when the NHS denies treatment, and usually that only comes into play with e.g. very new cancer treatments. Every citizen of the UK can use NHS services as a right, whether they pay taxes or not. If you have an emergency, you will be taken to an NHS A&E department. BUPA et al primarily provide slightly nicer rooms for inpatients, might be more flexible on times you can see a doctor, might provide more personalised information on general health stuff (e.g. "how do I lose weight/get fit?"), and might allow you to see a doctor slightly sooner for stuff that's not going to kill you. I do not believe that Americans as a whole are satisfied with what they have. I believe that you are, since you have significant income and can get coverage for anything you like. I talk to people on a daily basis who have to worry about what treatments they are able to afford for their diagnosed disorders. For many of them, surgery is required for which they have to save up for a number of years and then visit another country, while paying extortionate (in relation to their income) prices for life-saving medication all the while.