Death from "old age" (talking about those 85+)is actually death from heart disease (number 1), cancer (2), alzheimers (3), or stroke (4).

Heart disease at end of life can be a drawn out pain with the heart not strong enough and it causes fluid to back into the lungs, the lead to death from pneumonia or some other breathing issue like COPD or some shit. It is pain for a few years with diminished quality of life and most days are spent just fighting to hang on. Those that die of a heart attack are the lucky ones if it is quick enough, but still pain and terror for several minutes at least.

Those that die from cancers at this age, well... it's cancer. Try and find anyone's story of having a peaceful time dieing from cancer when they are old.

The alzheimers deaths can take many forms. Anything from alzheimers dimentia and your brain deteriorating until it literally forgets how to function basic bodily functions like breathing; or it could be something like lewd body, where you are hallucinating most of the time trying to cope with a world that is literally changing in front of you by the minute with memories of your past blurred with imagination and nightmares that you can no longer suppress.

Then you have stroke patients. Most of these people have had multiple strokes by this age if this is how they are going out. This is where from the first strokes they have lost entire sections of their brain and lost major functions of things. For some it is as simple as loosing their speech and no longer able to physically talk. Others have a quite opposite loss, and lose their language. They talk all day and it is nothing but nonsense. Both groups are locked from communicating in meaningful ways and frustrated eternally. Therapy may restore some levels of communication but it all depends on several factors. Then there are the strokes that take out your hearing, vision, sections of memory, perceptions, you name it. Some of these people even suffer from a basilar stroke and are stuck with the ever terrifying "locked in" syndrome.

Of all of these, sure, you might want to hang of for a bit. But after your one person you have spent your life with, the one person who understands you, and the one person you have been fighting through all your daily pain for- they are going to die. Then why fight for more pain? Just go out with dignity and do it together. You can make an event out of it and let those around you know how good it has been and give people some closure.