the game is progressive in nature, when new content comes out, your best gear from last content won't be enough to clear them, that's where the new entry gear comes in, they would be better and easier to get, this is done so to allow new players an even playin field when they join. It's like a soft reset, just like how this game transitioned from 1.0 to ARR. You can also look at WoW on how this works.