Im going on 5 years on my 6S+
Best iphone i have ever needed.
Best iphone i have ever needed.
I looked into it a bit, and found that this happens when a piece of dust gets into the lens, which steals the focusing of the camera, so it shakes because it oscillates focus from the field of view and the piece of dust. Sadly the camera module needs to be replaced, which can be purchased cheaply but medium tedious difficulty to replace - or pay to have it done not as cheaply.
The other thing that went wrong, also apparently in an OS update, is that TouchID won't work anymore. The hardware isn't recognized.