You can buy a tree that is already twenty feet tall.
Not a sapling. Not a five gallon pot. A mature tree, with a full canopy, delivered on a truck and lowered into your yard.
It costs a great deal more than the small version of the identical species, which would reach the same size on its own in ten or fifteen years.
People buy the big one constantly. Moon Valley Nurseries has built a company across the Southwest doing almost nothing else.
Which tells you the customer is not really buying a tree. They are buying the fifteen years.