Unless you are arguing for euthanasia, this is precisely how many people die. I've seen it with both of my parents and my father in law. It is a sad fact of life. All of them had the best medical care possible, but when the body is at the end, there is simply nothing you can do.
You want my opinion, I think inactivity is the biggest killer of old people. Most of them in homes literally have nothing to do but stare at the walls.
Generally people who keep their mind active do tend to age better. I’m not saying you’re going to be what you were when you were 20 of course, but...
In that regard, my family has fared quite well. The worst was probably my grandmother (who was in a home). She had a lot of little weaknesses that all added up, but her end came rather abruptly from a stroke.
She could have done a lot better than she did, but also at the same time I reflect that there are people much worse off. Some of her problems were her own fault too because she never exercised and also destroyed a kidney because of popping prescription drugs for years.