A leather quiver takes up two inventory slots. You can store thirty arrows in it. Those arrows can only be fired if the quiver is equipped on your back, taking up the slot that a backpack would use.
Now, here's the problem: you can keep a fully loaded quiver in your backpack and take the arrows out of it manually whenever you need them since loose arrows in your inventory can be fired. There is little reason to equip the quiver.
Am I missing something here, or are things a little unbalanced? Is there any reason to equip quivers?