Frankly, the key factor, as I see it now, not as I saw it prior to having to deal with it, is one of quality of life, not just living. Frankly, the quality of life variables are one's every person must decide upon for themselves. For example, some folks may consider that merely being incontinent is sufficient for them to feel their life has come to ruin. Others may feel that they wouldn't want to go on if they are physically incapacitated, but mentally fine (or mostly so), and still others may consider that mental incapacity is their limit. It comes down to what one is willing to deal with and how one wants to live.
Personally, I think there ought to be
life ending services available for a fee just as there are life creation services available for a fee. I think that because while we may as a society permit caregivers, family members, etc. to assist in a life ending action, it's quite a lot for many individuals to accept. I suspect too there are folks who want to die, but who don't want to know they are doing so "right now" or "ten minutes from now," so to speak. Some -- caregivers/family or folks desiring to die -- may not be able emotionally to face head on the reality of what they are doing even though they cognitively know its what they want or what their loved one needs/desires, understandably, thus the call for services such as that noted.