I used to play pick up basketball but stopped because I didn't like the overall lack of structure.
I liked playing on a consistent team, which typically doesn't happen even during somewhat organized pickup events with the same players on regular occasions.
I also severely dislike the idea that there are no shooting fouls, which means hacking the **** out of someone every time they try to shoot becomes an effective strategy to disrupt their flow and make the game a drudgery to play.