I am inspired by the front yard landscaping of Western Portland, OR. Hardly any property has grass lawn. Grass is replaced by lush ground cover, ferns, wild grasses, flowering bushes, etc.
It's great when you don't have any kids that need space to run around, and it's very low maintenance, but I suspect that they're going to run into issues when selling the place, there's not a whole lot of demand for a 4 bedroom house with no lawn, and the place isn't really laid out such that you could just replace the deck with a lawn.
There's a law that says they have to have a patch of grass?
In some cities, it's actually the council's job to mow them as well.