You know, I don't know if there is a fundamental advantage to driving on one side of the road or the other. It is too bad that the whole world didn't pick the same answer. Same thing is true about mains voltages and frequencies. At least in the latter case there are some arguments to support one answer or the other, but unfortunately, the best answer locally isn't necessarily the best answer elsewhere. I am personally sure that any one of the choices in the world would have been "good enough" the world over.
At this point there is too much capital investment in the choices made to make world normalization practical for either of these systems, so people will be arguing about and lamenting these things for a long, long time.