Sounds like you are the one making assumptions, and the assumption is that people want a PC on their phone. You can think of it that way, but reality says otherwise. People don't want a PC on their phone, they want a phone. And when they upgraded to a newer phone, they don't want to relearn things. Apple delivers that. The closest thing on Android side is Xiaomi, and that is if you stick to Xiaomi phones. Even Samsung always change things on every new iteration of their skin. My facts are from actual chats with people like I mentioned above. They are no fans of Apple per se, and they don't care. All they want is a phone that they don't have to tinker like a PC. The iPhone happened to be that. These people have better things to do in their lives than having yet another frustrating "PC" in their pocket.
If you want a PC in your pocket, it's your choice. The topic here is about user retention of iOS. Your argument doesn't support the data.
It is not about needing PC in pocket. It is about the continuation of the ways we are used to. For someone new to IOS, can they even comprehend the complexity on how to just attaching files to email? Or why they cannot just plug in the thumbdrive to phone and copy files? Or why the heck they needed to close the app just to go to settings? Or why when deleting item sometimes you have to press on it to make it wiggle and other times you need to slide on item to call up the delete button - instead of one consistent long press to delete?
ps I am just responding to your generalization that Iphone is "easy" to use. It is not true.