For those who don't know, Keaton was amazingly dedicated as a comedic stuntman - a silent era Jackie Chan (he was less popular after the silent era, but kept working until his death in the 60s). From Wikipedia: Garry Moore recalled, "I asked (Keaton) how he did all those falls, and he said, 'I'll show you.' He opened his jacket and he was all bruised. So that's how he did it—it hurt—but you had to care enough not to…
> He opened his jacket and he was all bruised. So that's how he did it—it hurt—but you had to care enough not to care. I don't want performers to risk their safety, health and life for my entertainment. Obviously I cannot stop it, but I can stop watching those who engage in things like this. (And I don't just mean the stunt performer, but the director, the producers, the studio and the franchise.) I have unsubscribed…
I mean, they pretty much all do to some degree. It's not healthy on your body to do eight Broadway shows a week. Or to be constantly switching between all-day and all-night shoots on a TV show. And performing a role of high emotional trauma every day for weeks or months takes its own kind of toll too.
Obviously nobody should be at risk of life or of permanent injury, that goes without saying.
But getting bruises while doing stunts, that's just what being a stuntperson is. Nobody is forced into it. And this is why there are stuntpeople in the first place -- it's not just for skills. Sometimes the regular actor could do it fine, but there's no time in the schedule for their body to recover afterwards.