The US customary units have a lot advantages. For example:

In Fahrenheit, 0 is really cold while 100 is really hot. In Celsius, 0 is kind of cold while 100 is damaging to life.

With feet and inches, you can easily divide a foot by 2, 3, 4, and 6 with no repeating decimal digits. It's the same reason the ancient sumerians used base 60 for their number system.

With liquid measure, a cup is roughly what would be considered a serving with a meal while a litre is one hundred millionth the distance from the equator to the north pole, cubed