This should be totally obvious to everyone. Even from a heartless economic perspective, properly funding the NHS more than pays for itself - people who have health issues have reduced productivity, and that means less taxes for the government, and that they end up paying more in benefits, and the impact on people’s health tends to mean that one issue becomes a much bigger issue or other issues… leading to things to get worse to a point where they can’t be ignored and it’s much more expensive to put right.
There is no good reason to continue to underfund the NHS. It is entirely ideologically motivated - despite the fact that publicly funded healthcare makes complete sense, it just doesn’t let the elite extract enough wealth from the rest of us!