Why would we need people "in the workforce"? That's not even a futurist question; why do we need such a high labor participation rate today? Is there some stack

Why would we need people "in the workforce"? That's not even a futurist question; why do we need such a high labor participation rate today? Is there some stack of widgets going unmade we desperately need? Are we fighting a two-ocean war I didn't notice? What won't last very much longer is this antiquated notion that two thirds of the adult population "should" be working. It should probably be more like 25% now, and that will only decrease. (NB: it could be 50% working half time, 75% working one-third time, etc.) This notion of people having "jobs", and that being a normal thing, is fairly new in the story of H. sapiens (and it's only reaching parts of the developing world now, right as it's becoming obsolete).