It is widely hypothesized that the physiological factors that lead to high economy and those that lead to high VO2max are to some extent mutually exclusive. When scientists have tried to predict the limits of human performance, they ask, "what if one person had all the best values we've ever recorded in a lab?" But chances are, that's like asking, "what if someone could be in shape to run both a WR in the 1500 and in the marathon at the same time?" Sure, an elite distance runner is going to be way, way better than most people, even outside his specialty, but once you start reaching rare air, some characteristics that help you be the best in one area will preclude you from being the best in another.
So VO2max is pretty much irrelevant once we're already dealing with high level athletes. Where it has more potential is in screening young talents to select the ones who have the minimum capacity necessary to be world class. That's why it's common in countries where they have nationalized Olympic sports programs.