My guess would be that fractions with a powers-of-2 denominator were used in pre- and early-industrial contexts and remain in use today by long tradition, but t

My guess would be that fractions with a powers-of-2 denominator were used in pre- and early-industrial contexts and remain in use today by long tradition, but thousandths started to be used only later in industrialization when the benefits of a base 10 system were more clear