A bar chart titled "Deaths from Wars & Cars" the Leftmost bar is WW2 at 78M, followed by Cars 72M, Mongols 39M, Taiping 25M, Ming Qing 25M, 2nd CN-JP 20M, and finally WW1 19M. A note at the bottom states "Showing estimate midpoints"
Because it doesn't matter. Wasting time on finding out if grandma had a tumor, cardiac arrest, organ failure, or a seizure ultimately doesn't matter because if it wasn't X, it would've been Y, or Z. The organs don't grow back the same quality, and it detotiates every time, so at some point you are frail, and all your organs are failing, and it's gonna get you sooner or later.
Wasting manpower to find it out for statistics sake is just plain dumb. Also nobody wants doctors to cut their 90 year old gramps just for the sake of statistics.