One possible answer is that near-perfection (the perception of "Job's" products), including recognition (widespread adoption), is attainable at any given moment in time, but typically unsustainable long-term...given human and technological constraints...

It could be entropy, as some have suggested, or simply the difficulty of maintaining a level of quality one has become associated with producing...

Maintaining the (high) level of quality one has reached is difficult enough...

Incremental gains on a level attained become much more difficult...opportunities become infinitesimally smaller...