Bad take of the moment: Brits and Aussies are even bigger slobs than Yanks are: https://www.statista.com/chart/35765/share-of-respondents-said-they-wore-casual-fashion/
Infographic: The Nations Keeping it Casual

This chart shows the share of respondents in selected countries who said they wore casual fashion regularly.

Statista Daily Data
@MikeElgan I think it's also problematic to assume that each place thinks the same sort of attire is in the same category of attire.