"Not to mention feet, inches, etc... so called imperial measurements."
Imperial measures in most of the world, but different non-metric 'US' measures in the country that is the biggest obstacle to sensible universal measurement.
US versions of fluid ounces, cups, pints, quarts, and gallons are all different from Imperial measures.
Then again, there are at least a dozen different definitions of 'ton', several of which are not even measures of weight or mass. At least with a tonne (aka metric ton, aka 1000 kg) you know what you are measuring and how big it is. Even worse, in some cases imperial convention uses different tons for different materials, but you don't know whether everyone between you and the original measurement knows that... or whether one or more of them have helpfully converted. Similar issues arise with ounces, and pounds. At least the pounds are probably units of weight or mass. Relatively few people know that a hundredweight comes in two different sizes, only one of which is 100 pounds.
Miles is another one, of course. Ignoring older versions of the measure, there is no easy way to know if the person giving you a city to city distance is using statute miles or nautical miles, unless they explicitly tell you which it is. Ditto aircraft speed.
The US is stuck half way through conversion, with the consumer facing side still in the dark ages. Case in point - you can go into any US hardware store and buy 'quarter inch' glass, but that hasn't actually been made for decades. The factories produce 6mm glass, which is sold as quarter inch glass. Just finish the job, already!
As a bonus, they occasionally lose a spacecraft, or someone's airliner runs out of fuel (Gimli glider) because the archaic measurements are still allowed to mess up the world by inciting confusion. I'm just glad Air Canada tends to have quite competent pilots, or they would have lost a planeload of people somewhere near Gimli.