just a very silly argument against that:
if the most skilled person in WoW would keybind everything, s/he would magically lose skill?
good reasoning right there.
the sole reason we keybind is so we don't have to look for skills/have higher reaction time/obtain higher consistency.
it's as easy to remember a keybind "shift 3" as it is to remember where exactly you put the corresponding ability on your bars.
all in all you will improve your uptime, consistency and reaction time by switching over to keybinds, not instantly because at first you will have no idea where you put any of your skills, but after a while it will become natural.
all in all, freeing up your mouse for TARGETING (even tho this can in most cases be negated by boss-specific target macros, which also improves your uptime, no joke) and PLACING ABILITIES (such as aoes because it is undoubtedly faster to already have your mouse at the place you want to place your aoe than go all the way over to your bars and back to where you want to place it) and ROTATING YOUR POINT OF VIEW is extremely important as you can't do either of those while clicking (unless you keyboard turn, and then you're a lost cause to start with).