Re: I am not convinced either way on this
You don't seem to understand what a monopoly is, nor a legal undertaking.
A monopoly ISN'T illegal. The competition authorities may prevent you buying up other companies to create one, but a monopoly in a given field is perfectly OK providing you got there by creating the market or by being the seller of the most popular products in it.
Once you reach monopoly status there are restrictions over what you may do. You are not allowed to leverage your position to get you into another market for example. Microsoft were convicted of leveraging their position in operating systems to force their way into the market for web browsers. To settle this case they gave a legal undertaking to present users with a browser choice screen when the system is setting up. They broke this.
In order for Microsoft to (retroactively) comply with the agreement you were mildly inconvenienced. Tough.
Apple don't hold a monopoly in either PCs or phones, so they are not subject to these limitations. You can't just count devices made by a manufacturer, you count the whole class of devices otherwise you could claim stupid things like "you can only run Samsung software on Samsung TVs".