Science and engineering all use metric in the US. Automative all moved to metric voluntarily. I know construction is still imperial.

Its mostly consumer facing things that still imperial. And if you go to Canada its pretty common to see $/lb printed along side $/kg. People often talk about height in feet and inches, weight in pounds.

Its really not that different.

Machinists still do a lot of work in inches.

Machines last for decades and can’t practically support multiple standards. There’s an enormous amount of inertia in such a system.

Similarly aviation uses feet for altitude in most countries.