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 response highlights the differing values and priorities between the two cultures, where the U.S. tends to emphasize work and productivity, often resulting in longer workweeks, while the Netherlands places a greater emphasis on work-life balance and social welfare, which can contribute to shorter workweeks.