NHS is a central political tool as well. Every party knows the will die if the NHS fails, so opposing parties heckle eachother accusing eachother of how they are failing the NHS and how they will fix it.
It is not perfect, but it works.
I had cancer. Got picked up really early because of an NHS GP at my place of work. Was in hospital in no time at all. Treated and cancer free. Literally did not spend 1 pound on anything.
Had I been in SA, my medical aid would not have covered it fully. Would have eaten up my medical savings account.
So yeah I am biased, but in my experience it is a system that works.