Enmity was never an issue, threat is easy to hold, just stay in tank stance and gg. The problem comes in the form of having to also push dps for raid encounters and the stances were just clunky at best. The reason it still exists is because you still have to have tank swaps. I can't think of any currently in ffxiv, but there are some bosses in wow who are immune to taunt and the tanks actually have to find another way to deal with the tank swaps.