I've never understood the people who say , "I'd never ever DNF." When I was coaching, a DNF never bothered me if it was warranted.
I loved what Athing Mu just did. She didn't try to half-ass that mile. She competed. She thought, " I'll do what I do in every race I do - try to win."
Eventually physiology caught up with her.
She covered 800 in 2:10.00, 1200 in 3:15 but then ran a 34.97
I love that than doing what so many US pros would have done which is run in the back and then kick big to PB.