Keeps the dust down.

The larger the property, the further from your neighbors so you hear less of what they are doing.

Stops erosion.

Mainly at this point it keeps the dust down.

In some place it is very hot and grass helps to keep the temp from the ground down. Most people would prefer a grass lawn then a dirt patch. Given I could plant tons of flowers but that requires lots of work. I don’t have that kind of time. Also if you have kids you probably don’t want them playing in a flower garden. You wouldn’t have many flowers.

Walking or playing in the yard is much nicer and cleaner then playing in the dirt.