Large grass lawns were a sign of wealth and power for the aristocracy and gentry from the feudal system. When they had large numbers of serfs working their small plots of land and paid a tithe to the landowners it meant that their land could be turned over from agriculture to pleasure.

Growing a big, unproductive, biologically inactive lawn is basically saying “I have so many peasants I don’t need to grow vegetables” and then morphed into the quasi status symbol we have today for suburbanites to complain about each other’s while the planet dies around them.