Firstly, I have no desire to use what I consider the Roman Catholic form of measurement. I might be an atheist, but I’m an Anglican Atheist (may the non-existent Lord be with you…).
Obviously the metric system is easier to use. That is clearly obvious. It’s based on the number ten. Division is easy and conversion between grams and kilograms is easy. A kilogram is just a thousand grams. Done. Easy.
The problem, however, is that no one (well, almost no one) uses the metric system on a daily basis. We didn’t grow up with it. We don’t want to convert to it. If we had started off with it, the metric system would be fabulous. But we didn’t. We use pounds, gallons, and the like. We like it that way.
Not using the metric system makes us unique. Yes, we are only one of three countries that don’t use the metric system, along with Liberia and Myanmar (Burma). While that isn’t good company to be in. One has terrible flags, and the other just terrible in general.
Regardless, the United States isn’t terrible. It’s fantastic, even if Americans can’t spell things properly. The United States Customary System makes the United States unique. It makes America great in the same way that common law makes the Anglosphere great. Converting to the metric system would be costly and annoying. No one wants it.
Imagine going to the grocery store and suddenly all of the products are measure in grams, kilograms, and the like. That would cost the store money or it would cost the manufacturers money. They would have to reprint labels and boxes and come up with absurd measurements. Something that used to be measured in ounces would now be measured in grams. This would produce an odd, strange-looking number. A 5 oz. can of tuna fish would now be a 141.75 grams. Who wants that? Sure, the manufacturer could make the units in even numbers, like 140 grams of tuna. But that would mean you’d get less tuna in the can, otherwise the manufacturer would have to change the dimensions of its container. And on top of that, the store would have to relabel everything. It would be chaos.
No one wants chaos. Unless it’s the good kind of chaos, which is never really good.