I’m typing this on an iPhoneX I got on day of release. I’ve had a new battery and it’s still perfect. I kept telling myself I’d wait for USB-C, but now it’s here I’m just not bothered. I think the only reason I would have to upgrade is when mobile apps drop support for iOS 16. What “must have” feature are you using to justify an upgrade?
You are conditionned to feel that you have to replace old gear with newer gear with marginally incremental features. This is a basic principle of modern capiralism and aggressive marketing. It is also a leading cause of resources overexploitation, soil and water pollution and the climate crisis.
You do not need to replace your phone until it stops working.