As someone who works in the NHS, money isn't the only problem. Under Blair, lots of money was dumped into the NHS. It helped - waiting times for appointments came down, times to treatment improved etc.
But compared to the 1980s, there's about half the number of hospital beds. There are almost no step down or recovery hospitals where you were properly rehabilitated before going home.
Cancer survival rates are poorer because of diagnosis. The time from diagnosis to treatment is the same as everywhere else but patients are presenting later with symptoms. Hence the campaigns to see your GP if you have a cough for three weeks for example.
In General practice, the "huge" pay rises awarded with the 2004 contract has steadily been reclaimed to the point where some practices have shut down, and more GPs are retiring earlier or moving abroad. There's a drop in recruitment numbers. Along with increasing population and unlimited public demand, this means there's going to be difficulty in getting appointments to see a GP.
Insurance based schemes in the end are there to generate profit for someone else. Whilst the US has insurance based schemes, it's massively costly. Insurances may not cover everything or may set exclusions for pre existing health problems, which means you would have to pay extra. A lot of the population can't afford to do this in the USA. A lot don't even have health insurance.