Ovi won't catch Gretzky because he's simply not good enough. Never was, and based on his current performance, doesn't seem he ever will be. Good? Yup. Great? Debatable. The best? Nope.
As a fantasy debate, it makes for interesting banter, but the reality is Gretzky was and always will be in a league of his own in almost every offensive category. No one will likely ever erase his records.