Pull-ups are a multijoint exercise and require minimal equipment to perform. They can be progressed or regressed to increase and improve upper body muscular strength, endurance, hypertrophy, and performance of tasks that require upper body pulling strength. Proper technique and control should not be sacrificed to perform more repetitions.
Ronai, P. (2016). Pull-ups. ACSM's Health & Fitness Journal, 20(2), 24-27. doi: 10.1249/FIT.0000000000000192