You are so fucking wrong. Alright time for a rant. Because why.
Reason the metric system caught on so quickly is, as
@Overly Serious explained. CONSISTENCY. Weight goes in grams. Volume liters. Distance meters. Grams turn to miligrams, or kilograms. Liters turn to mililiters or kiloleters. Meters into kilometers or milimeters. Etc. When factored by 1000. This isn't just intuitive. It isn't just easy. It is SOUND from a mathematical perspective. If everything has the same equations all you need to do is find a constant and you'll get the equivalence. Passing volume to distance is easy, passing weight to volume also easy, etc.
When using different units, like centimeters, milimeters, etc. All you need is to multiply or divide x10^whatever. This is very. Very. Very easy to do. And even then we keep forgeting the factors because humans are, by nature, dunces.
Using imperial system weight, distance, etc. All have their own fucking constants for every step around the way. If you got 0.3m you got 3dm or 30cm. See how that work? If you got 0.3f you got 3.6inches. And note how I had to use a .x there. That means I'd now have to go check what's the smaller version of inches and multiply that by that factor until I had 0f3ixwhateversywhocares.
Sure you can simplify. But you can't actually always simplify in science. And in metric. When we have to expand a little bit. It's just 7.7268471947, in imperial it looks like 7'10''5'''1'''' etc. Which takes more space, adds more constants, and just suuuuucks.
Then how to fix that. Well there are just 2 ways other than being a dick and ignoring the problem. 1 is to just use only inches and use 6.86865i and ignore other units. Essentially using metric system but with a different name behind the number just because you want to be obtuse. Second option is to use leters. In hexadecimal for instance a is 10, b is 11, c is 13, etc. So it could look like 7.a51. But then you have to remembet what kind of decimal you're using on every spot along the chain. And why. Just. WHY.
And this is before the fuckups happen. Because again. Scientist fucks up in metric? All he needs to do is spot where he forgot the conversion and add 10^x there. Easy as fuck, you just gotta move the point back and forth. Scientist forgets units in imperial and he gotta get a fucking calculator to get it to miles. Because you couldn't just make it so the "dot" is the same as the conversion number, no, you had to be fucking special.
And that's before we get into who defines the units. Because as seen in this thread IUs vary depending on what the WHO says that month. I'm sure that won't cause massive issues. Nah that's totally better than just using objective measures like the speed of light in a vacuum. Which don't change based on chinese whims.
I know how obtuse this can get because certain processes change between chemical energy and phisical energy. And one is measured in cals and the other in jules. And then resistances also have different units, etc. And let me tell ya. When you get to that point and now need to remember 3 different fucking conversion factors and check where you left them. Oooooh boy. Boy that's a fucking mess. So I cannot possibly concieve why you'd want to add more of thst shit to the mix. Just to be fucking special.
Also, if american scientists tried changing bsck to imperial they'd actually crash american academic for years while pupils get used to conversion. There's a reason SIs are used. Because when spanish, french, british and german scientists create equations even if the name is fucking weird we can easily get the math. American scientists wanted in on that. And didn't want to remember "wait this was made by a non american so now I gotta factor... let's see. Density? Well then I have to convert both volume and weight that's grams to ounces and liters to galons. Wait no this is density by height to the surface so I also gotta convert meters to feet. Oh wait no I forgot liquid changes density by temperature so on the fifth equation I gotta change celsius to farenheit... yeah that's it. Right? Sp this gives me a pressure of wait how did I have to convert pressure again?" NO ONE WANTS THAT. Literally no one. Systems of measurement are supposed to simplify your life. Not turn a 1 hour project into a 3 day search for the lost city of El Numerado.