Here is the definition of monopoly from the U.S. FTC. Apple does not meet this definition.
“That is how that term is used here: a “monopolist” is a firm with significant and durable market power. Courts look at the firm’s market share, but typically do not find monopoly power if the firm (or a group of firms acting in concert) has less than 50 percent of the sales of a particular product or service within a certain geographic area. Some courts have required much higher percentages. In addition, that leading position must be sustainable over time: if competitive forces or the entry of new firms could discipline the conduct of the leading firm, courts are unlikely to find that the firm has lasting market power.”
In addition, courts and governments have more frequently applied sanctions where the product or service involved is considered necessary for life or health. Smartphone apps are not in that category.
