From a statistical standpoint, the best athletes in any sport are those individuals farthest (outliers) from the mean (average athlete). For a given sport, you will have outliers distributed farther from the mean (more standard deviations) with the more overall athletes competing/trying to compete in the sport.
So my theory is the best athletes in the world are in those sports that everyone wants to participate in or can participate in. For example, hockey is very limiting because it requires ice or an ice rink, skates, pads, helmet and other players. And most of the world doesn't even try to play it. So, compared to other sports, I'd think hockey players are not great athletes.
On the other hand, soccer has few requirements - a ball, a field and a few other players. Plus it is played all over the planet. Therefore, soccer has to be one of the sports with the best athletes.
Similarly, I'd also argue distance running has to be very high, whereas cycling is probably pretty low.