You missed my point. My point is that if Apple wants to add this now, it's going to cost them engineering resources.
You think side loading on Android cost Google "nothing" to implement and maintain? No, it costs them engineering resources to support that feature. It's a good feature to support and it's beneficial to users. But it's not free, it doesn't magically insert itself into the Android codebase if they "comment out an `if` statement" as the GP suggested.
Also, Android is gradually adopting many iOS-like permissions and security models. We recently updated our Android apps related to reading and writing to the file system. Why is that? Because the free-for-all they shipped with was heavily abused by developers.
You think side loading on Android cost Google "nothing" to implement and maintain? No, it costs them engineering resources to support that feature. It's a good feature to support and it's beneficial to users. But it's not free, it doesn't magically insert itself into the Android codebase if they "comment out an `if` statement" as the GP suggested.
Also, Android is gradually adopting many iOS-like permissions and security models. We recently updated our Android apps related to reading and writing to the file system. Why is that? Because the free-for-all they shipped with was heavily abused by developers.