A mile is from the Latin for "one thousand"--one thousand paces. Probably for most people a pace (considered as from when one foot leaves the ground to when it is on the ground again, while walking) is more like a bit over 5 feet rather than 6 feet.
The other practical advantage of the English system is that the number of inches in a mile is almost the same as the number of astronomical units in a light year. So if you make a model of space where the earth is one inch from the sun, Proxima Centauri is about four and a quarter miles away, and the other stars are as many miles distant from your starting point as they are light years away from the sun.
I thought a cubit was the distance from the king’s nose to the end of his middle finger if he held his arm out straight, and a yard was two cubits—from one middle finger to the other if both arms were held out straight.