but if you counted all people who didn’t have a job then you’d skew the statistic even more by counting voluntary stay at home parents and other people who don’t work because they don’t need to.

Why is this important? Number of people with jobs / number of people is a statistic that obviously shouldn’t be 100%, but if it goes up or down that’s something we should pay attention to. If we suddenly have a large spike in people who stay at home and don’t work, we should at least understand why