Because you don't need to water artificial grass,this is ideal where water is scarce or in hosepipe/sprinkler ban areas.For those on water meters it also offers a saving;during warm weather it's estimated that as much as 75% of residential water is used to irri.
You only need to carry out light maintenance once the grass is installed,so no more lugging the lawn mower around,or getting down on your hands and knees to weed the grass.This,of course,generates you savings on time and up-keep costs,and is particularly useful if maintenance isn't possible or practical.