A human that looks around while driving is still taking in a lot of real-time input from the environment. Assuming they're not a terrible driver they examined t

A human that looks around while driving is still taking in a lot of real-time input from the environment. Assuming they're not a terrible driver they examined the upcoming environment and made a prediction that at their current speed there were no turns, obstacles, or apparent dangers before looking away. If they didn't fully turn their head they can quickly bring their eyes back to the road in the middle of their task to update their situation. If a GC has to pause the world to do its job there's none of that background processing happening while it's "looking away".