Sony is one of the few Android vendors that mainlines the device drivers for their hardware, so you can reasonably build the newest AOSP version and go to 7.1 if you feel the inclination.
How would rooting your phone (to be clear: enabling the ability to "su" to root, thus giving you full power over your system) screw your camera/image quality?
I totally understand flashing 3rd Party ROMs where they can't speak to the hardware as well.