Ask any of your peers why they upgrade phones. 9/10 will tell you their old one was too old and slow to run modern software or the battery was toast, and that happens in just a few years for some phones. My roomate will probably be upgrading their iphone X soon, not because they want a new iphone, but because its starting to do weird things like not be able to take screenshots and is overall far slower than when he first got the device. Same story with the 6s the X replaced years ago. New phones haven't been cool for a long time, we've been buying the exact same slab of glass for like a decade.