It's not a monopoly. By definition. It's not even close. That's all I am saying. So we should stop with this absurdity of talking about Apple having a monopoly. Apple does not even have majority market share in any of the markets that it participates in.
Depending on who you ask, Apple may or may not have a monopoly on their App Store. I’m of the opinion that you can’t just redefine a “market” to be what you want that would make someone a monopoly. Is Target a monopoly on what it sells in its stores?
If it's not a monopoly, there needs to be some other word for it. It's not equivalent to retail stores, where if you don't like Walmart's price you can shop at Target, because the cost of switching from one phone to another is prohibitively high. Until everyone walks around with an iphone in one pocket and a Samsung in the other, it's something akin to monopoly.
Nothing about the original argument changes, people are just being pedantic about which word is used. Duopolies can be just as dangerous as monopolies, and to the original commenter's point, duopolies are definitely capable of monopolistic behaviors.
I advise people to just use 'duopoly' and to avoid letting arguments like this distract from the main point, which is that Apple has an outsized control over the entire mobile market and uses its control to unfairly prop up its own software offerings like Apple Music over Spotify, to lock consumers into its ecosystem making it difficult for them to move to other platforms, to force third-party devs to give Apple a substantial cut of their own profits even when they aren't interested in leveraging Apple's services, and to outright shut down competing mobile services that don't fit into Apple's vision for what they want the mobile market to be (Google Stadia, etc).
