I think we're mostly contextualizing this to the US, where Apple has over 50% (~58% last I checked) of the market, which is where most competition of their own apps exist. Last I checked, iOS had ~24% of global market share.

Regardless, 14% of 3.5 billion is still so ridiculously large that each phone OS should be considered their own market, not competitors within the same market. You wouldn't consider a microwave and a toaster oven to be in the same market, even if they're both kitchen appliances that heat up food because they're individual markets. Not all people want a microwave and not all people can afford a toaster oven due to space or financial priorities. In the world of tech, where there's no real definitive line between markets and any one company can have an audience of more people than any monopoly in the past, the old ways of drawing a line in the sand based on a percentage no longer works.

> Last I checked, iOS had ~24% of global market share.

The link in my reference showed Apple at 14% of the global smartphone market for many years. Do you have a reference you think is more reliable?

Similarly, they have Apple in the US at between 40-49% the last 6 quarters:

https://www.counterpointresearch.com/us-market-smartphone-sh...

While that's not 14%, it's certainly not a monopoly. Consumers don't have to worry that if they switch to one of those 51% that they're on a platform that nobody else will use. Epic and Spotify and Kindle could make tons of money selling to the other 51% of phones in the US; and if Apple's terms were actually difficult for them to make money from, they could just not make iOS apps, and be perfectly healthy companies. The fact that they do sell on iOS shows that they are making plenty of money, just not as much as they'd like.

I'm pretty late to this, but your statistics are smartphones shipped, which isn't really representative because people with iPhones tend to use their particular model for longer than Android users, which go through phones quicker for one reason or another. I was going off of operating system market share, which is primarily determined by web browser user agents. It is more representative of active phone users and doesn't need to rely on who's buying a new phone or who's sticking with their older one.

Again, the smartphone manufacturing market isn't in question, it's the software markets that are tied to those smartphones.