Deshaun Watson in 2018

When you move/run so much the chances of injury increase dramatically. Watson would have been rookie of the year if he hadn't been injured. He doesn't move in a way to prevent injury. You will hardly find an NFL quarterback who runs a lot and has a long career.

Why doesn't Brees ever get injured? Well he trains specifically to avoid injury first of all, but also he hardly runs the ball ever. He just plain doesn't spend much time with the ball. And he bends like a mother******. Same with Brady. That and he is a tackle avoidance freak in the pocket and he gets rid of the ball very quickly. He always is close to the league leader in sack avoidance. Yeah, we've had some pretty good offensive lines, but a lot of the goodness is Brees' ability to move in the pocket. The athleticism of Brees is one of the most underrated parts of his ability.

Aaron Rodgers for example, his career will not be nearly as long as Brees/Brady because he relies so much on his scrambling ability.