Android has 75% market share, it's not like you can avoid it, they have practically a monopoly. As much as people like Apple here, it's nowhere near the same market share as Android.

Also you should put quotes around open-source, AOSP does not run on any real device due to a lot of android parts being private + private drivers. It took me one month to run a custom kernel on my Samsung to get the basic hardware working, it's as far as open source as you can get. Android is a "look but don't touch" kind of open-source.