> Also, on macOS, you were sold the explicit ability to run whatever software you want. It's purpose is to run software from third-parties.
I agree with that, and I think there would be a much stronger argument if Apple changed MacOS to remove this ability when it is a very well-established ability of the Mac platform. Of course, Apple almost certainly will not remove this ability, not because they want to be nice or they want to dodge antitrust allegations, but because they know that doing so would lose them customers.
But with iPhone, my argument is that this is absolutely not the expectation fostered by Apple's marketing or held by the vast majority of iPhone owners. Apple has always been very proud of its App Store and its (supposedly) strict vetting process to protect iPhone owners from malware, privacy violations, and other junk. Now, I personally think Apple should be much more restrictive about what apps it allows in the store, because there is a vast wasteland of abandoned apps and junk apps. If anything, the iPhone seems to have gotten less and less restrictive over time (the first iPhone didn't even support any third-party software, after all). I have a lot of trouble buying the argument that any significant number of iPhone owners expected to be able to run any third-party software they want to.