Radix,
Prior to AoS, Item ID was used to ID Magic Items, It used to be that when you looted you would get an Item, say, a Long Sword and all you would know was that it was a Magic Longsword. You would need Item ID to find out it was a Supremley acurate Long sword of Vanquishing.
But when AoS was launched everything came as ID'd and therefore the skill became useless.