[crispyambulance]

I understand what you're getting at but it's not that easy: it is not a clear-cut decision when it happens to your family.

Usually, old folks develop an ever growing list of aliments which add up over time, usually one serious medical crisis every few months to a year until their number is called.

Moreover, many of aliments of old folks aren't "terminal". You can't take your octogenarian mother to the hospice, for instance, because she broke a hip, had a stroke, got sepsis from a UTI, or suffered a venous ulcer that put her in a wheelchair (all those happened to my mother in a span of 2 years).

Also, "dementia" (not to be confused with Alzheimer's) is a side-effect of something else rather than a condition in itself. A simple infection is enough for an elderly person to develop dementia to the point where she does not know where she is. Even a pain-killer regimen requires careful management to keep the patient on a knife-edge between lucidity and la-la-land.