There are end of life issues beyond languishing in retirement (or a lack thereof) and loneliness. No matter how much money you save or how well your physical body holds up, eventually your mind will dim. If you're lucky you'll just slowly fade away in pain that's really only obvious to those close to you, if you're not you'll go the way of the late Sir Michael Atiyah.

At least for me, spending time with people in the final stages of their lives has made me believe that euthanasia may very well be the more humane way to pass. The thing that was the actual person is very often long gone by the time their body ceases operations.