AFAIK that's not how it works. For example go look up Microsoft's monopoly. The commonly held believe is Microsoft was declared to have a monopoly on personal computer OSes but that is false. Microsoft was found to have a monopoly on OSes for Intel based machines. So by that same logic Apple has a monopoly on OSes for A series (A10, A11, A12) based smartphones.
https://en.wikipedia.org/wiki/United_States_v._Microsoft_Cor....