[1] https://financesonline.com/number-of-smartphone-users-worldw...
I'd argue that monopolies should be judged on country and not worldwide. As each country has different iMessage popularity, apps restricted by region, earning power, phone availability, etc.
Apple does have a monopoly on the markets running on all their devices, from apps to media, for ~900 million phones. When Apple doesn't completely own the only available market service to it's hardware (that it exclusively gives itself), it still charges a 30% fee to it's competitors for access to it's markets while actively blocking everyone else.
https://www.cnbc.com/2020/10/06/house-antitrust-subcommittee...
https://www.eff.org/deeplinks/2022/02/eff-appeals-apples-mon...
So sure. Not a monopoly. But also not far from a monopoly as you claim.
Their software moat with IOS is everything.
Software itself is innately a hugely monopolistic industry.
IOS is Cisco's router OS. Apple did license it though, to prevent any potential lawsuit...
Companies have a limited output of the materials needed to make a computer. If Apple tells one of these companies you now have an exclusive relationship with us, or else, what is that company going to do?
Anyway, Apple has a monopoly of platform, which is measured between its own base, rather than as an absolute number compared of what % devices are iPhones.