It seems YOU don't understand what monopoly means.
https://www.merriam-webster.com/dictionary/monopoly
> exclusive ownership through legal privilege, command of supply, or concerted action > exclusive possession or control
You seem to be under the impression that only one type of monopoly exists (IE: Android exists so Apple doesn't have a monopoly).
But do you realize that that's no the only thing that can be monopolized?
So again... on the iPhone platform? who has "exclusive possession or control" over apps on the iPhone?