Look at the cat and mouse game the EU and apple are playing in regulation.
Where actually they are a full monopoly in the App Store market. Only way to solve it, is to break it up.
They do, they absolutely do. What’s worse, it turns out they have a full monopoly in MacBooks, computers running macOS, iPads, and iPhones.
In other words, no they don’t. The legal definition of monopoly is not solely, “if there’s only one participant in a market, the participant in that market has a monopoly”. There is necessarily more to it than that, because if that’s all it was, literally every company selling a product would have a monopoly in that product.
You could argue that markets are just the wrong kind of social formation for mediating software production and distribution, since software is not a commodity.