In a nutshell, it is your better / best way to do damage when fighting 3+ / 4+ enemies since the total damage output you can do is 110pot x number of enemies. None of your attacks can do more in total against mob groups so its better GCDs spent for doing AOE damage than attacking individually.

That said if one of the mobs is particularly low, it can't hurt to do single-target damage on it to finish it off.