But it just doesn't happen, though. There are no prominent cases. Why fight so hard to prevent a possibility that is so remote?
It's like the carbon blades that girlfriend-murdering Pistorius had on his legs. In theory, sophisticated blades made out of space age materials would be superior to human legs. If in no other area, but in the fact that you can't tear a blade like you can tear your Achilles. But they still let Pistorius compete against those with real legs because Pistorius wasn't going to be Usain Bolt even if he was born with legs, and because the dude who finished 10th in the Olympics is probably not going to cut off his legs in order to try and gain an advantage.