The majority of Chinese residents don’t live in metro zones, work office jobs, and eat fast food, though.
Also, very common to find reusable metal straws (and cups and utensils) outside the US. Korea and Japan both overwhelmingly favor washable utensils, as do cities south of the US border (I stopped seeing disposables once I got outside Mexico City proper and I never saw them in Jamaica or Cozemel outside the airport/seaport). There are zero disposables in Havana. The very idea is alien to them.