How often do you finish a round with the same ball you started?
For me it’s pretty rare. On about half the rounds I play, I lose a ball (often in plain sight). Since I play cheaper balls, I’m not particularly inspired to look longer than a couple of minutes. A ball that hides from its owner deserves to be abandoned.
I also regularly hit trees and cartpaths that scruff the ball to the point where I decide to switch. Sometimes an aggressive wedge out of a sand trap has the same effect. I don’t know that my game has enough precision for a scruff to make a difference, but I need every edge I can get.
Finally, I sometimes find that a ball has just become uncooperative. These miscreants resist my best swings, instead choosing to fall short, or go long, or slice or hook. After a few errant shots, I’ll send one of those badly behaved balls are sent to the bottom of the bag for a time-out.