It would be done in a second if there was value to it. Especially large companies as often there are bonuses based on profits. Or do you actually think directors and CEOs would rather make less personal income?
It is goofy that people actually think productivity would remain the same when working far less hours and believe the same number of houses (or insert any product here) would be built. Or that a pilot test would remain accurate if the people involved in it did not know it was a simple experiment. Tell me if those companies that experienced more productivity, why did they not continue to implement it?