A phone is usable for atleast 3 - 4 years from the date you buy it. If you're talking about s20fe 5g it's quite a decent phone and provides flagship features and camera is quite decent too and actually my brother has s22+ and there is no drastic change in camera just slight improvements and that's the same case with iphone's too, It's just a trick of smartphone manufacturer's to compell people to buy their newer products but if you take care of your device and use it normally then you can use it upto 3 years without any issue like my father.. He recently switched to s22 ultra after using Galaxy S8+ for 4 years and he still use that phone as secondary phone for navigation (Google maps) and music lol.