This; I used to build my own custom ROMs for my Android devices to get a close-to-AOSP experience + Google services + rooted app store, but it was a lot of overhead and maintenance, plus still slow and unstable compared to iOS. Now that iPhones have had great battery life + excellent performance for a while, combined with great cameras and apps that are iOS-specific, it'd be very painful to go back to Android.

Good point. When you buy an Android phone you're forced to put custom roms and new bootloaders on it. The phones do not work without doing all that.