Only the rich can afford to own nothing/exert effort to have empty space without consequence.
Reminds me of the reason that grass yards exist: to show the world that one can afford land for the sake of owning it, rather than for growing crops.
A dirt yard is sufficient if it was to show off land. Grass is not required
Lawns are for much more than just flexing. It's an outdoor part of your property which is flat and open enough to use for various activities and purposes. I don't know where people get such a cynical idea that this is THE reason anyone has lawns.