I read yieldrcv as saying that people not dying is good on its own merit, so we don't need an economic argument. The survival instinct is enough justification on its own.
We may not need to contrive some reason why saving lives will actually save us money, and therefore saving lives is good.
If you need an economic reason to save lives, you will have to do incredible gymnastics to justify medical treatment for old people, for instance.
So don't do the acrobatics. We can just say that medicine is good, actually.
yes, jtlienwis is making an economic argument to justify the treatment. yieldcrv is arguing that the economic argument may be invalid (i.e. it's a "fairy tale" to believe the treatment will pay for itself through economic activity, but there are non-economic arguments to justify treatment (i.e. "we can justify having an option for people’s self preservation" - the treatment is an option for self-preservation and self-preservation can be justified on other grounds)
I don't think the top level comment was inherently about money, though. "Contribute back" can mean non-monetarily, or even be implying an indirect monetary gain from them contributing non-monetarily to their families.
Economics is devilishly difficult to really efficiently predict. More reliable lifespans and a larger elderly population can affect the total flow of money in ways nobody can properly imagine, positively or negatively.
From a younger perspective, the effect of eliminating cancers from the equation implies a lot. What is more expensive to the world, years of cancer treatments and palliative care to somebody in their 70s, or somebody living healthily through to 90 years old before dying from heart failure? What about the family cost of caring for a sick elderly relative?
