In general, modern advances have maybe added 10+ years to an average adult lifespan. The quality of the added lifespan is harder to assess though.
> Our days may come to seventy years, or eighty, if our strength endures
Is it? In a sense, the choice is still available to adopt the hunter-gatherer lifestyle, if you wanted. I don't know many who would want to do that.
Nonetheless, i'm not sure that the last ten years of my Dad's life (suffering from vascular dementia) were particularly good for him (I know that they were super hard for the rest of us).
I think the general point is that it's hard to trade-off the quality of those extra years, which is the point I was trying (unsuccessfully, it appears) to make.