But more broadly, the arbitrariness of the workweek—and the American obsession with how many hours it contains—underlines an important truth about the nature of work: Because an individual’s contribution to a company can be hard to measure, everyone seizes upon time spent working (an easily measurable data point) as a proxy for how much work is actually getting done. In other words, workers’ output can require so much effort to assess thoughtfully that companies focus unduly on bulking up the input—whether that makes workers happy or not.
Source: Why Can’t There Be a Four-Day Workweek? – The Atlantic