Do they have Cool Whip where you come from?
They have equally disgusting guck in every country.
Do you mean England or Spain?
If you mean "the United Kingdom or Spain" the answer is "take your pick". In the UK, the construction products industry went metric without any compulsion in phases between 1969 and 1972. We didn't even join the EU until 1973.
What has that to do with the question?
You wrote "when you buy sand or gravel at a lumber yard or a home improvement store, they are sold by the cubic yard." without qualifying which locale you were referring to. In every country of the world, except one, such materials are sold by weight in multiples of 1 kg.