The 8-hour workday. It’s practical, but it’s not productive. Unfortunately, it’s the standard way of thinking in our society. We try to squeeze out productivity from knowledge workers by putting them in a box for 8 hours and demanding productivity. It’s not optimal.
Most people are just sitting there for the last 2 hours, drained from their mental energy. The alternative is to split up the day into multiple chunks of work with rest and other activities in between.