Consoles are also effectively a duopoly, and yet Microsoft has argued that they should be allowed to keep third-party app stores off the Xbox while also signing on to the lawsuit to try and force Apple to open up their own.
I feel like you stopped reading my comment as soon as you hit the word "duopoly". Look at the specific reasons I gave why phone AppStores are different: they are increasingly necessary for everyday life. COVID-tracking, political interaction, school courses, paying for parking, etc. etc. The day XBox becomes one of the few ways to do these things, and not primarily a means to play video games, then it would be appropriate for the calculus to change there too. You can bring up Keurig coffee cups too, but the implications just aren't the same.
ios isn't a monopoly, there is always the other option. The option that has six times the marketshare.
again, this is literally about shutting down any possibility of a company ever offering a "walled garden" model. It's not that apple is dominant in the market - they're not. You have many many alternatives to using their devices, they're about an eighth of the market. But even that eighth cannot be allowed to exist, that business model has to be shut down permanently.
