How are the employers going to pay for the additional employees to work those 8 hours, while paying the existing employees the same salary for working 8 less hours?
I can only see this happening hand in hand with Medicare For All and the decoupling of healthcare from full time employment.
Service jobs, which are currently 80 percent of US employment, require the same amount of hours with actual people present, e.g. you can’t wait more tables, or answer more customer service calls, in 20% less time.
Removing the cost of healthcare from employers will allow them to allocate some of the savings towards employee salaries instead of healthcare insurance.