I read your article because of the title. Because I have been the caregiver for two people in my life. Because I have seen up close and personally what dying slowly is like.
I've written on the subject "20 Reasons Why Dying at Home is Better than Dying in the Hospital". So I perhaps thought you were going to discuss assisted suicide.
Because living in constant pain wears your desire to live away. I have seen it happen.
Your neighbor was very fortunate. Most of us will not be. Most of us will need assistance at some level before we get to the end.
I think you strongly overestimate the amount of "control" you have on your health after 60.
A life of "living healthy" will greatly improve your odds of not getting Type 2 diabetes but it will not protect you from random catastrophic illness. Like sepsis, or falling and breaking your hip.
Something like sepsis can put you in the ICU for weeks and start a cascade of health issues that leave you an invalid. Or you could get Covid and develop Long Covid (1 in 5 ).
Hell, the flu winnows out about 30-50K of those over 65 each year (1 in 1000 mortality rate each time you get the flu). Lots of people over 65 wind up in LTC after a really bad encounter with the flu.
A healthy active lifestyle improves your odds but there are no guarantees. Remember "Jim Fix" the guy who popularized jogging. He died of a heart attack, while jogging.
We desperately need to rethink "old age" and how to provide a way for people to have choices and be in control of what happens to them. Covid revealed that most long term care facilities are just places to warehouse seniors until they die.