To some degree, serving the "customer" by cutting labour costs to the bare minimum (as a way to minimize the cost of everything), means we create an awful existence for the people who depend on these jobs for a living. The tyranny of their lives is dictated by a consumer base who constantly demand lower prices and will shop elsewhere to save a dollar or two.
I worked in a supermarket for four years, but it was part time, while I was in High School and in my first year of University. I didn't need the money in the way someone working full time needed it. I was given consistent hours every week.
Working retail for a modest wage (say $25 an hour), with consistent hours would be a really great career for a huge swathe of the population. Lots of people (myself included) enjoy interacting with people all day.
A lot of more traditional professions have a better balance between physical work and mental work (skilled crafts, engineering in the traditional sense, or being a doctor all come to mind). Modern knowledge work doesn't have enough physical movement involved.
I wouldn't like to do it full time, but sometimes I wish I could spend 20% of my time doing something enjoyable but menial like stacking shelves. I think I'd hate doing it full time, but one day a week? Practically sounds like fun!