One might ask why that is; while some is surely due to natural decline in later years, one could likely also posit that the cost-fears leading up through that period (decades), and the general inability to get people to do preventative care throughout adulthood contribute to that significantly.
Indeed.
It is one consequence of a highly atomized culture. I suspect it happens because individuals are expected to take responsibility for their care (basically, this is the human side of cost-shifting and corporate planning around the care gradient available to someone at a given wealth level).
To someone at the end of their life, money is usually less interesting to them than a few more days of breathing. So the market provides.
To be clear, I'm talking about the absolute twilight of one's life that's reached regardless of levels of preventative care. I think there's potentially an opposite point that could be made: taking care of one's self can prolong this period and make it cost more. Someone who drops dead of a heart attack one afternoon won't have the same end-of-life costs as someone who gradually becomes enfeebled with age.
It's possible to meet the sole criteria of science, quality, and patient wishes with exploding costs. I think the OP's point was that money has to come from somewhere.