alt Hacker NewsIts not a communication overhead, it's that business owners want to maximise their returns on their fixed operating costs subject to the 5 day limit. One extra staff member in a traditional office is extra software license, extra seating, extra hardware, extra HR/payroll/insurance, extra risk, extra training etc etc.
Remember to thank your unions for the weekend.
If it was utilization of fixed capital that motivated the maximum-length workweek of today and centuries past, they wouldn't mind who was on the shifts or how many so long as there were three of them.