Because majority or monopoly is defined by their respective market? People keep spinning Sony does for PS5, when they should have said "console". But then the same people will argue console is small market, it needs to be gaming devices which include handheld or any other devices that could play games such as Smartphone. That was actually what Judge Yvonne Gonzalez Rogers spent 5 pages on her EPIC vs Apple case.

And why does a console, which is a single purpose appliance, used for Gaming. Be compared to a multiple purpose tools required for every day modern life?

A Train company has monopoly on trains? People would argue you have different type of transportation and you dont need train? All these argument are useless and completely misses the point.

Arguing whether it has a monopoly may not be a valid either. Standard Oil never had a monopoly, and neither did Microsoft in 90s going by those argument because Microsoft didn't have market shares in other computer like Server. And you still have linux and Mac on Desktop. You have a choice?

Ultimately it is about Anti-Trust. Too much power held by a single company that is also abusing that power.

And on the subject Apple can charge what it want. Yes. Perfectly valid argument in US America. But no, this wont fly in the rest of the world. Visa and Master can charge whatever it want for its network, until EU decide they have to lower their ridiculous fees and not to price average consumers a cut because they could get rebate from elsewhere. The same happened in AUS. Not a business model most countries are happy with.

And of course Apple supporters on 9to5mac and Macrumors are calling to pull out of small countries like Netherland as retaliation. In which I would use the same argument, if it is Apple's devices and Apple could charge whatever they want, it is also EU's market and they can do whatever they want. So yes, pull out if you dont like it.