Stupid useless lawns in front of houses need to go, yes. Grass is great for parks though. For urban settings trees and bushes are kings still.

grass [...] needs constant watering, fertilizing and cutting

I think you're not actually talking about grass but lawns.
Grass in the wild doesn't need any of that.

Grass really, really depends on location and climate. I literally never water or fertilize my lawn; it looks fine.

The worse thing here is ecological. I keep my mower set to 4", and keep my lawn a bit longer than my neighbors. I see a ton of fire flies in my yard in the summer, and see a fraction as many in my neighbors yard.

Short lawns are terrible habitat, which makes them good for sports or a children's play area. But 80% of my neighbor's lawn is just aesthetic, which is something I really don't get. Lawns are about as visually exciting as a beige wall. They're a waste of space.

You can use native grasses and there's no need to cut them more than like once or twice a year. There's nothing bad about grass! It grows in the wild as well. Lawns are hell though.

Imagine living in an area where grass grows everywhere and the only difference between your lawn amd the surrounding area is the grass height.

There are usually some ground cover plants that will do very well in most climates without watering. The clover is one example for temperate climates.