To each their own. The improvements in computational photography like automatically stitching a few pictures together for higher resolution and night mode are pretty incredible. And the improved dynamic range, resolution, and added wide angle lens are nice improvements.
I've updated every 2 years for the past 8 years or so -- even back then I never felt the need to upgrade the very next year, but by 2 years out I've always been pretty excited for the improvements. And this year that still holds, I'm excited to upgrade my iPhone X.
"Incredible" is a pretty big stretch. When you can calibrate the cameras yourself, the math isn't actually that difficult to work out. Also, there are plenty of us that use the phone in a "pro" sense as a mobile computing device, not as a photographer or film director.
I've updated every 2 years for the past 8 years or so -- even back then I never felt the need to upgrade the very next year, but by 2 years out I've always been pretty excited for the improvements. And this year that still holds, I'm excited to upgrade my iPhone X.