I don't know why people have such a problem with this. Nobody in the UK with an IQ above 70 thinks the NHS is literally free in the sense that no money ever changes hands. "It's not really free!" is a stupid gotcha that doesn't even make sense.
As we should be if we want a utopian society. Better than paying corrupted, monopolistic, lobbying US medical companies over-inflated prices for everything because people have no other choice.
The only issue with public healthcare is the government corruption that tries to kill or diminish public healthcare, but it's still a hell of a lot better for society than private.