While wide grip lat pull down maybe one of the most staple exercises you do on your back day, very few the importance of this workout. Some even skip this exercise for reasons of working on the same muscle. But in the case of this movement its also a lot about the joint of action along with the muscles involved. A supported compound exercise by nature, this is a exercise that involves the lattisimus dorsi, teres major, elbow flexors group and the lower fiber of the trapezius.
The joint of action that stands unique in this back exercise is the Shoulder adduction which none of the other back exercises perform. Almost all back movements use the shoulder extension and elbow flexion as the joint of action unlike the lat pull down.
This makes the movement perform the advanced level of the pull up where unlike in case of the pull up you lift your body, here the weight is pulled near your body. Any exercise to feel complete should typically focus on all joints of action involved with that particular muscle group. This where this movement makes the list with its shoulder a joint of action where all other weighted exercises focus on the extension including the narrow grip lat pull down.