I haven't been there myself, but I've had friends in this situation. Most friends, actually, are currently dealing with one or both parents in serious cognitive or physical decline. Mostly cognitive, it seems like.

Pushing euthanasia - nope.
But with the number of people that absolutely cannot take care of themselves - and the many more that are coming, with boomers getting older - something will have to give. Perhaps it'll be people refusing medical treatment.