This is a somewhat recent figure I found. https://9to5mac.com/2017/01/11/ios-market-share-kantar/
This is a somewhat recent figure I found. https://9to5mac.com/2017/01/11/ios-market-share-kantar/
http://fortune.com/2017/05/23/apple-iphone-gartner-market-sh...
But the essential point is that nobody can afford to ignore Android and building to iOS-specific APIs doesn't make sense.
The market within the iOS space is huge and if building an iOS only app using ARKit is more profitable then why not ? It's all about ROI. There isn't an equivalent for ARKit on Android and building one would be costly and time consuming.
For example ARToolKit is available for Unity, or even Anddroid.
https://artoolkit.org/documentation/doku.php?id=6_Unity:unit...
Unless you are targeting a specific audience (for example artists that use the iPad Pro) for most developers it really doesn't make sense to confine yourself to iOS.
There have been smartphones for years. Apple is pretty late to the game.
For broad market maybe, but for niche markets a good example would be ForeFlight https://www.foreflight.com/products/foreflight-mobile/ It's pretty much the gold standard among pilots, from private to airline transport, and it's IOS only. Makes support and dealing with fragmentation a whole lot easier.
Surely you are referring to some future point in time, because most can still afford to ignore Android, use iOS-specific APIs, and be profitable.