The system would require each worker to contribute just fifteen hours of labor per week
The irony of this whole thing is that fifteen hours of actual work isn't that far from what I do in an average week, but I'm still here forty hours. And I work with my hands, in a skilled trade in an industrial facility; I can't even imagine how much time-wasting a lot of white collar people do.
Outside of shutdowns, I could easily work three days a week with no loss of productivity. But that's just not an option.