In Colorado all 4 teams in state finals had 2 drivers. It’s one less thing for our main driver to think about and makes driving easier. I do have overrides that let me take full control of the robot if my co driver fails, but usually he is attentive enough to do pretty well.
My team uses two drivers, but not in the traditional sense where control of the subsystems are divided. Rather, the second driver adjusts minor things like the height at which the claw releases, as well as switching between different pre-programmed constants for our control loops depending on how many rubber bands we have on our lift/claw. They also have failsafes, like returning the arm to manual control if, say, an encoder or potentiometer gets unplugged during the match. Last year, they adjusted flywheel settings so that the main driver would never have to worry about how far away they were from the goal, they’d just line up and shoot.