The real reason I think Russ is so diligent about having a job is because the alternative is that he sits at home all alone with his thoughts. With no friends, no family who wants to spend time with him, no hobbies, and no responsibilities, he might leave the house once a week on a quest for discount cereals. There's only so many TV reruns you can watch, only so many porn sites you can fap to before it all becomes meaningless. By having something -- anything -- to do during the day, Russ doesn't have the time to dwell on what an absolute failure he is.