For the record, I am from a metric country and immigrated to the US as an adult. I still find American system to be more adjusted to human needs. E.g. temperature in F does not need decimals unlike temperature in C, tool sizing in inches is simpler (look at the sets of drill bits in different systems for example), tire pressure in psi (e.g. one of my bikes is 53 psi rear and 51 front, or 3.65 and 3.51 bars, you could say I could remember just the decimals, but another bike is 33 and 31, or 2.27 and 2.13 so no, it's 3 digits with bars vs 2 in psi), house dimensions are in even number of feet so much easier to find furniture, which is designed with this in mind, obviously. Miles are great to estimate time of travel by car, take 1 minute per mile of distance on a highway and 2 minutes in the city and you will be pretty close.
But, of course, the reason the American system is never going away is because it would be insanely expensive: you either will have to rewrite all building codes/standars/recipes with stupid conversions e.g 50.8x101.6 instead of 2x4 even though the lumber dimensions are not really 2 and 4 inches or scrape them and write the new ones using the more sensible metric dimensions but then you will need to scrape all the tooling you had and buy new, metric tools. All so you could say how many micrometers in a kilometer and feel smart?
