I personally think that Apple and other smartphone companies need to do a minor and major version release like you do with software. Every 3-5 year, do a major release. This way you create significant hardware/software features every major version, a hype that is well backed up, and at the same time keeps you working and improving and still making money out of it through minor versions. Plus, you also don't have to rely on planned obsolescence as people are gravitated towards the major version release naturally.