Sometimes, your market has just been saturated, and nothing else is needed for a while. I’ve heard of certain iphones that were built guaranteed to break down after a short warranty expires. Maybe that’s how market saturation has been handled up to now.
That denies the fact that users are keeping their iPhones longer because they last so long. If they were designed to break down post warranty, that wouldn’t work. That was a FUD (fear, uncertainty, and doubt) claim spread by Apple’s competition. An iPhone can run four or five years before being end-of-life and not being updated for the operating system. If the user replaces the battery when it gets chemically depleted, the device will run like new. . . But it will not run apps designed for later multi-core processors with super fast GPUs because an older phone doesn’t run as fast or as well as the later model iPhones simply because it lacks the capacity to run the newer apps as well.