Indeed. Sure, lawns do have their place, like for playing sports or for kids to play around. But otherwise, what a waste. Just plant some local flowers or whatever and have a meadow.
As an example, at some point my father stopped bothering to mow his lawn all the time (basically only once per year). It's now a nice meadow with all kinds of grasses. Frogs, butterflies, dragonflies, bees like it.
An additional issue with robotic mowers is that they tend to kill hedgehogs.