My hypothesis is that most of our "unproductive time" in the 40h workweek is just filler time spent warming seats, a direct result of there actually not being all that much work that a human can consistently accomplish in a week.

So, by removing the expectation that you have your butt in a chair 8 hours a day 5 days a week, the new model is "get everything you were already painfully stretching across 5 days done in only the time it actually takes (2 days), and let's all go home and enjoy the free time we otherwise would have spent scrolling on our phones under florescent lights and quickly tabbing back to Excel when the boss walks by."

I truly do believe 95% of office-based business would get the same "amount" of work done in this system.