[vidarh]

Unless everyone worked in base 12 numbers too, that'd be a mess. Part of the beauty of metric is how often calculations devolve to shifting the decimal point.

[Ekaros]

And nothing really prevents metric system from working in base-12. Ofc base 12 kilometre would be larger than base-10. But it still would work.

Base 10 really is used because our number system is base 10. And more so base 1000. Apart from some cultures.