The most likely cultural trait responsible for the difference in workweek length between the U.S. and the Netherlands in 2020 is: The U.S. culture prioritizes capitalism, while the Netherlands’ culture prioritizes health and welfare.
This reflects the fact that the U.S. tends to emphasize work and economic productivity, leading to longer average work hours, whereas the Netherlands places a higher value on work-life balance and social welfare, resulting in shorter average work hours.