There wasn't an ageing population back then
We're all ageing. There was always someone at death's door needing medical care. it just used to happen a bit earlier in life
nor was there an epidemic of obesity, diabetes etc.
-but there was far more smoking-related illness and heart disease about.
We also allow people to openly abuse it
Full Fact attributes 0.3% of NHS expenditure to health tourism (I assume this what you're wittering about) - but around half of that is British expats who come back and get treatment they're no longer strictly entltled to! Can't be treated by those smelly foreign doctors, can we.
Most people would agree that the current model is not sustainable.
Show me an alternative model that doesn't entail people being denied access to healthcare due to poverty, and I'll listen. Until then the NHS is no better or worse than any other other. I accept that there are some inefficiencies but these happen in most big organisations.