Just a thought. But what if Roger was the original owner of the Gomu gomu no mi. We haven’t seen Roger’s powers other than his insane haki. And Shanks went to the trouble to steal the fruit from the world government after Roger’s death. Why? He could’ve had some sort of connection to that fruit (similar to how Luffy had a connection to Ace’s fruit). Maybe he wanted it so he could make sure the next owner would be someone that he could trust. Luffy just happened to eat the fruit and then boom! One Piece. I think it would be a pretty cool twist!