When you do pull ups, it targets different muscles of your body including deltoids, pecs, lattisimus dorsi, abdominal, cardio, and a lot more. Those muscles perform better if you go through regular pull ups. Its also work on other muscles of your body such as your traps, teres major, rhomboid, infraspinatus, erector spinae, and external oblique.
There are different muscles groups on your shoulder and pull-up work on them too. Thus, targeting a wide range of several muscles groups, pull ups are being a blessing for you and your body. So if you make pull ups as your routine exercise, you are helping your muscles work in a great combination.