Per the parent, the challenge is to convince governments to take your proposed approach. Repeating the argument to try to convince a HN crowd is not just non-productive, but counter-productive if it doesn't move toward this goal.
Taking away property and/or converting investments into a utility when a business becomes too successful results in a lot of nasty byproducts and most governing bodies will shy away from this.
Instead, you likely see the issue completely side-stepped. Nobody truly cares about labelling Apple a monopoly or declaring iOS to be a somehow accepted as a market onto itself - they want a change in behavior.
The challenge is how to side-step this when per the letter of the law, they have literally done nothing wrong. For instance, the EU will likely get a lot of pressure due to new regulations being solely against US-headquartered countries for the primary benefit of companies in the EU.
However, iPhone is not a commodity, it comes bundled with an OS and plethora of apps and services, the whole ecosystem.
per this report ( https://www.imore.com/apple-takes-75-smartphone-profits-desp... ) it says apple is taking over 75% of profit pool of the market, despite selling only 13% in units.
If we identify monopolists using bottom-line approach, then Apple will be a clear monopolist. As would be Facebook and Google. as they should be, if lawmakers truly cared about public good