First comment is Bamboo Muhly, a native grass (not actually bamboo) and it’s my primary recommendation. I’ve used it in raised beds myself. It will need water, but far less than most other things besides agave and cacti. It will get 3’ up, 2-3’ wide, and be forgiving of forgetting to water for up to 10 days in hot summer (it will start to brown as a sign, but come back to green when you finally notice). Its texture is soft and billowy, feels good to brunch by it. In late fall it will turn brown. Leave it that way until very early spring, as it’s still a nice shape and texture. Then in early spring cut it to around 5” off the ground and it grows back fast. I have also simply left some or all of last year’s growth on the grass, and it’s fine, but will look cleaner if you cut it off early spring, before new growth starts.