I'm not sure speed alone, by itself, is a solution. If you speed down a game by, say, 70% there would probably be no difference than if you sped it down by 90%, since there's a limit to what the character can do in a given second. Mario, for instance, once you jump, there's not much to do until he actually lands.

Suppose the same would happen if we had the capability to speed down time in our actual lives. Sure you could dodge bullets and win F1 races from time to time, but the actual day-to-day tasks, that take the majority of our time wouldn't be improved much. If you need to eat lunch, eating it in an optimal way won't give you much advantage in comparison to regular people that don't take the fork to their mouths following a perfect parabola.