Bonjour,
Eternal confusion between weight and mass 
As Frenchie, I don't find anything simpler that the MKSA measures and suffer when I watch videos evoking pounds, eight sixteen of an inch and x miles per gallon, question of educatin 
I can divide pounds by ten, one hundred or one thousand just as easily as I can kilograms. But depending on final use there are far more options than just grams, as there are ounces, grains, pennyweights, drams, scruples, and a host of others that relate to specific systems within the whole.
Eight sixteenths of an inch = half an inch but there is seven and nine sixteenths available on either side as well .... ;c)
Miles per gallon is no more or less convenient than kilometers per liter.
Once again I will say that metric is the best way to go, by far, in virtually any science related measurement, and certainly some engineering venues as well. However, other systems do provide other useful perspectives, if you know how to properly utilize them!
Can you tell me why is it that you don't use a metric clock then?