I am American and hate imperial units especially ounces

Carter was transitioning the US to metric and then Reagan killed it.

I think the USC units are currently defined as fixed multipliers on top of SI units. The USC pound for instance is defined not as "the weight of this reference object" or "the mass associated with these multipliers on top the Planck constant," but as 1 lb = 0.4536 kg (assuming four digit significance for now)

It's dumb, but at least not entirely as dumb as having them defined as their own thing.

TBF we use metric wherever it's needed as in science, engineering and the military. Imperial is more for everyday use and at least some of it, like feet vs meters, is more intuitive than metric since it's basically the length of a grown man's foot.

But again, wherever it actually matters, we do use metric.