Of course they have to go to the john occasionally. But there are so few close calls because of the low numbers of planes relative to the size of the airspace. When you get millions of people in the sky, there will be a lot of close calls every day, and even a minor wreck in the sky results in catastrophe.
Pilots do more than just sit there and babysit the autopilot. They have to be able to deal with stuff when anything goes wrong.
Of course they have to go to the john occasionally. But there are so few close calls because of the low numbers of planes relative to the size of the airspace. When you get millions of people in the sky, there will be a lot of close calls every day, and even a minor wreck in the sky results in catastrophe.