Umm... but how is the mAh capacity relevant? You can have 10K mAh if your hardware and software is inefficient. I am no Android hater, just recently defended Android for a lot of things https://medium.com/bricksnbrackets/are-iphones-really-better-than-android-phones-e7c1b9b049bb

but efficiency is simply not its best feature for no other reason that it has to run on any hardware. I haver the iPhone 13 Pro and get 2 solid days out of a single charge.