A big chunk of the arguing in an antitrust case is about how the relevant market should be defined. A plaintiff bringing a suit against Apple might define it a

A big chunk of the arguing in an antitrust case is about how the relevant market should be defined. A plaintiff bringing a suit against Apple might define it as "the market for iOS apps", but Apple's lawyers would argue for something much more broad, like the "the market for computer software". My hunch is that the court would probably land somewhere in the middle like "the market for mobile apps." Apple's still a big player there but far from a monopolist.