What separated people before, and what STILL separates them is skill. Now, to be fair, there's a LOT of nuances to PvP that SE has just never taught people, and the information was, at best, an easily missed note in patch notes (such as Icebound Tomeliths in Shatter being 50% more magic resistant), but largely, anyone who knew what to do before and could adapt to the way their job is played now still stands out as a skilled player.

I have to agree that trying to force fit each job into 9 buttons isn't so great, as not all jobs play the same anyways. And though they've teased the idea that they can add to it, that seriously needs to happen, among plenty of other balance changes.