On the off chance that anyone is still interested in the OP, and as someone who’s cared for hundreds of people who’ve died, I wish old age were still considered a cause of death.
Most of my hospitalized patients are over age 80, and many are over 90. Sure, they’ve been admitted with pneumonia or heart failure, but the truth is that a lot of them are just plain old. If it wasn’t pneumonia, it would be kidney failure. If it wasn’t heart failure, it would be a stroke. I mean, there’s just so much wrong with them as a result of being old, that something’s gotta give.
Here’s a typical example - 93 year-old man with advanced dementia, multiple previous strokes, congestive heart failure, Parkinson’s disease, and chronic renal insufficiency (i.e. chronic mild kidney malfunction). He has a fall, gets admitted to hospital, then gets totally delirious, then develops pneumonia, then experiences a worsening of his kidney function, then aspirates his breakfast, then gets worse kidney function, then seems to have had another stroke, then goes into worse heart failure, then gets a urine infection, then gets worse pneumonia, then dies. Not only is it arbitrary to choose a specific cause of death, or label him as dieing from pneumonia, it’s misleading. He died because he was decrepit. He was decrepit because he was old.
FWIW, the British Medical Journal (BMJ), in its obituaries of British physicians, often lists the cause of death as “old age”.