Apple has been consistently making it harder to make money off iOS users without sharing that revenue with apple. Furthermore, they don't allow side loading of apps, their own apps have special api's that their competitors can't use, etc.
I could go on and on.
> The exclusive possession or control of the supply of or trade in a commodity or service
Since Apple has, at most, below 50% market share in developed countries (and a much lower market share in developing countries), they do not possess a monopoly on the smartphone market.
If we compare Google's marketshare in end user email, video hosting and search, we can see Google is a lot stronger in many markets, than apple is in their best market.
(I wish I could use an iPhone, but having to use Mac OS for development is a real turn off, considering how sucky Mac OS, in my view, has ever been.)
Buying a mobile for your personal use means you have to develop for it?