Longitudinal study on mask usage

This is a bit of a rhetorical question. It's based on the simple fact that the percentage of the population wearing a mask in public in July 2022 was; 86% in Japan; 43% in the U.S.; 21% in the U.K., and 5% in Denmark. Japan was not alone among the Asian nations, all wearing masks in the 80% or greater range. Why might that be?