What is a "low-paying job"? Young? Unskilled? Other culture? You're describing slaves. If someone is working at a job, ANY job, for 40 hours a week, then they should be able to live a comfortable life for the other 80+. And at this point in history I'd lower that to 30 hours since we have more than enough productivity and automation. Which is why the author mentions that 15 is lowballing it.