We can discuss the other cases, but since 2013 I don't see any other gymnasts coming close to what Biles does.
She had an off day with two falls and a not so great floor exercise. Despite that, she still deserved the title (I guess she was a bit overscored, but in the end wouldn't have made much of a difference). It's not her fault that the system favours difficulty. It's not a great look when a gymnast with a fall wins gold (that also happens frequently in figure skating), but unless FIG changes the code, the win for Biles was fair.