Let alone things like theorycrafting which was way less extreme. \
All these things have allowed for the higher echelon of players to develop a lot of ways to deal with possible encounter mechanics, which in turn allowed the devs to develop more and more complex/difficult encounters, and so on.
My point isn't that the top players were bad - no, they were as good as they could be. But that wasn't very good since the limits weren't exactly hard to reach.