For me, pull ups are the epitome of consistency. Progression, being able to practice something consistently to become better. For me, pull ups are hard. But its something that I want to be able to do. When you work o them continually, I can do more at one time. Starting then back up is definitely harder to accomplish more than a couple.
With anything in your life, the results aren't instant. You have to pay your dues and put in the work.