A person I know and her H were out on a neighborhood walk a few years ago when he suddenly went down. A neighbor performed CPR and saved him.
I have another friend whose H’s life was saved a few years back when a lifeguard at a pool where he did laps performed CPR on him.
Very recently someone collapsed at one of the nearby lakes and a doctor who was there did CPR and saved him.
That’s who I can think of off hand right now. That said I will have a DNR if I become terminally ill and also after a certain age (not sure what age that will be).