There is so much time, effort, and physical waste that is generated by slightly redesigning phones every year purely for the sake of making sales (as opposed to meaningful improvement upon the existing design or introduction of a new hardware feature). Think not only of people upgrading for the sake of it, but all of the cases, screen protectors, and other assorted accessories cast in plastic for previous models that are garbage now.
It would be nice if we could just space these things out to 5 years or so now, because that's probably how long it takes for anything to change enough to justify a new model.
No one is forcing you to buy anything you don’t want.
Also, the OS and apps need to take advantage of new hardware, so it’s not a surprise if your seven year old phone becomes slower.
If you don’t like the status quo then I would go with a non-iOS and non-android phone like pine phone, Mairena, librem, or anything else that based on a more open Linux distro.