https://motherboard.vice.com/en_us/article/j5geby/the-iphone-is-guaranteed-to-last-only-one-year-apple-argues-in-court

As Apple readies its annual reminder that the expensive smartphone in our pocket is now obsolete, you are, no doubt, wondering if it's time for a new iPhone. The yearly refresh and the iPhone Upgrade Program have conditioned us to want to get a new device every single year.

But most of us don't need a new phone, of course, and lots of our iPhones will probably last at least a few years, especially if you're willing to replace the glued-down battery, which has a limited lifespan. But on this iPhone Day, it's worth considering how long Apple expects an iPhone to last. When it released its iPhone 7 Environmental Report a year ago, Apple wrote that it "conservatively assumes a three-year period for power use by first owners," which is "based on historical customer use data for similar products."