Perhaps a lawyer can jump in for this question: when a company is accused of antitrust behavior, isn't there a requirement that consumers are forced to use the product, or are at least significantly disadvantaged if they don't?
I mean it in the context of, no one is really forced to buy an iPhone, anyone can easily switch to Android. I contrast that with Microsoft's antitrust in the 90s, where they had 90% market share and much of the software was only available on Windows, which de facto forced everyone onto Windows.