One often overlooked thing is that as a market becomes saturated with a product of a company with total market share, those already-sold products increasing become that company's competition. So long as the company does not resort to special laws from the government (i.e., does not seek to obtain a coercive monopoly), it must continually best its existing achivements. This is sometimes accomplished by adding features that give the company access to new markets for its products (selling a smartphone after gaining experience with portable music players).
Secondly, on an individual basis, the desire for excellence always comes from within, and results from an inward ethical focus. The goal for those true strivers is not set by or on the existence of others: it is not "let's destroy X," but rather, "let's bring this new thing into existence." In a truly innovative company, this attitude predominates because it is held by the majority of its employees.