Well no, WM, however much pain we're in, the Drs do know that it will be got through and a future is ahead.
I'd have cheerfully let them chop my arm off without anaesthetic at some points but I wouldn't have chosen to die and no Dr would have considered it an option.
It's quite different when someone's going to die very soon anyway and you/they don't want their final hours/days to be spent in unspeakable agony. I can't bring myself to type more about Mum, it's too personal, but morphine is different when you have it long-term (years). She was quite definitely 'herself'.