Even Wolverine has been hurt by power creep though. When he first appeared he healed fast. Now he can litlerally be burnt away to nothing but bones and regenerate. It is ridiculous how far his healing factor has been pushed and it has hurt him as a character because he is basically immortal at this point which makes boring. It take out any tension in the story when you know the character can not even be hurt let alone killed. It shatters the sense of illusion your reading a good story. We all know he is never going to die, but to not even have the risk of being injuried then whats the point.