In the professional music scene, you can go for an entire career without running into one. It is a relatively small set of outliers, and even then, there is a narrow set of genres (most of them Western and modern) where a professional player can get away with not reading or writing music.
Even in the poster child of learning by ear, Jazz, something like 99% of session and pro players learn to read music.
Even in the poster child of learning by ear, Jazz, something like 99% of session and pro players learn to read music.