What's so scary about working 21 hours a week? Bit of an error from the actor there I think. Though surely even a 21 hour day on Pluto wouldn't be that bad given it's day is 6 times that of Earth. Plenty of time for a game of badminton and a movie once your shift is done
I'm only up to episode two, but the 21 hours a week definitely refers to the amount of sleep Cordo's getting (3 hours a night x 7) not the work he's doing.