Last spring I got aggressive about the front lawn. It was full of dandelions. I sprinkled a weed killer and fertilizer, and some grass seed, and for most of the summer it looked almost decent.
Then in early fall, some kind of weed started growing. It has continued to spread, even through the winter. It's now covering most of the upper half of the lawn.
It's "Creeping Charlie". You know what? I'm going to let it take over. It's low, it's green, it's evergreen, it has tiny leaves and tiny purplish flowers, and it laughs at most weed killers. It's edible, and smells nice when mowed. I can still spray or sprinkle for dandelions and crabgrass without apparently hurting it.
Sounds like it's easier to keep than grass, and needs less mowing. I can't think of any reason one would prefer grass.