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.
Big reason to cut the grass is to keep pests away from the house.
That said, I rather consciously arrange deadfall along one steep bank between our house and that of a neighbor so as to encourage/foster lightning bug egg laying/larvae/pupae.
Like, yeah, there are more interesting things to do with your lawn but they all require more effort than dropping a robot charging station and letting it do its thing.
Also the clover patch is probably gonna regrow, mine do... tho I don't try to ground them to the ground