Apple has been good at one thing, it taking a mediocre product and make it useful even pretty. Each iteration of a product they successfully absorbed has a relatively short life cycle because of Apple's relentless innovation. The premium for an Apple product is extremely high and makes them too expensive for most.
Apple deserves to do well in all its niches. As long as it can maintain its premium value they have nothing to fear from its devoted public. The Apple formula is "we do better" and, it is its eternal challenge.
The smart phone market, the PC market have one competitor for Apple, it is the industry. Apple produces clones where the industry produces variety. There are many types of PC or smart phone. What is as relevant, they are sold in a wide price range.
With Apple fighting legal battles to prevent yet another Android phones to be sold, Apple is effectively behaving like a monopolist. A monopolist that insists on the exclusive sale of its products. A monopolist who does not care about the whole market.
When you compare Microsoft with Apple, they are both monopolists. Microsoft however allowed others to earn their crust. The Microsoft tax on computers prevents the sale of computers at the bottom end of the price range. The Apple premium strangles innovation outside Apple, its patents prevent an industry from developing and finally it keeps affordable smart phones from finding a willing public.