I have a hot take on this: I don't think iOS and Android have long for this world. In five years, phones will just be an AI device. Local compute when possible, cloud compute when required. The OS will be whatever the AI dynamically creates for the user's tastes and requirements. People won't buy apps anymore. They'll create them on the fly as needed. In rare cases where an app purchase happens (such as a YouTube subscription), the AI will facilitate the purchase with Google's AI.