I would work 4 days for 80% pay. I would work four 10 hours days for 100% pay. I’m not sure that those solutions will provide the best business outcomes though.
I also bet, business outcomes would be improved on a 4/8 for 80% pay system. At least some of that work output on the lost day would be shifted to the other 4 days--since work tends to expand to fit the time allowed.
Without a study of white collar productivity decrease from a 4/10, I cant accept the statement as a "common sense" premise.
I do better remote sitting on my coutch until dinner programming away and write off fridays...because nobody notices that most of the organization becomes nonresponsive after standups at the end of the week.
Otherwise it is probably a loss.