Breaking pitches measure dexterity. I don't mean to diminish their importance, because it's the area where the most amount of coaching effort is placed. That's because it's changeable. You can learn these new tricks and discover hidden skills. It can often alter a career by several degrees.
Some pitchers excel using only the fastball.
Rare pitchers can compete only with their dexterity and control. Nobody succeeds without knowing the science. That's why I mistrust young pitchers. Young guys are dumb. Their talent is measured by a single standard, which is constantly declining.