Not only is it easier to build and maintain apps for iOS, people spend a lot more money on that platform. That Android market share is, in large part, driven by developing nations that aren't going to spend a lot of money on buying software on their mobile devices.
That could certainly change in the future, but I just want to illustrate why just talking about the number of devices might not be the best indicator for which platform you should develop applications.
https://themanifest.com/app-development/android-vs-ios-which...
Not only is it easier to build and maintain apps for iOS, people spend a lot more money on that platform. That Android market share is, in large part, driven by developing nations that aren't going to spend a lot of money on buying software on their mobile devices.
That could certainly change in the future, but I just want to illustrate why just talking about the number of devices might not be the best indicator for which platform you should develop applications.