Where's the trade off for Priest cloth?

Back when WoW was first released you were presented with a character creation screen. On this screen you had a choice to make about how you would spend your time in this wonderful game. At that time the decisions that you made were important because of certain trade offs. In the implementation and creation of the evolving world, where have the trade offs gone? This is especially true of priests.

Back in original launch there was a clear trade off for playing a priest. You would have cloth armor which meant that you were wearing a paper bag into combat, with the hope that those with plate armor would protect you. To make up or this priests were given the ability to have more healing than any other class.

Currently, we continue to wear paper bags into combat, but for some reason our healing has become subpar when compared to other classes. So I ask you, where has the trade off gone from rolling a cloth wearing class. When put next to a toon that crits more, has more mana regen, HoT's, and buffs that contribute to a party more (Yes we do have spirit that gives spellpower but, oh that's right it get's overridden by another healing class shaman), and not to mention have both spell, melee, and healing abilities I ask again where is the trade off. I just want a simple answer to a simple question. Please help me understand why after all these years I've been forced to /facepalm?