Back to the nicely-designed landscape at Univision's corporate offices in Phoenix. Forget their novelas or variety shows with women in clothing a couple sizes too small. Think instead of ample room.
This view looks dense, but...
With the dark wall and vertical accents as a backdrop, a broad area of granite gravel (negative space / void) keeps the budget for plants (positive space / mass) and their water usage lower. It is visually more powerful than if no ground showed.
Same area, but at a 90 degree angle to the above image:
We all like the sound of water in the desert, so note the negative space of paving in front, then positive space of the water feature and related walls, then negative space beyond that, then positive space(s) beyond that with the Saguaro cactus / Carnegia gigantea grouping, Gray Brittlebush / Encelia farinosa, Creosote Bush / Larrea tridentata, and other plants.
Alternating layers of positive and negative spaces read well, too.
Chuparosa / Justicia californica, a native Sonoran Desert plant, beckons what it is named after, a hummingbird to pollinate it.
Hummingbirds are known as chuparosas in Spanish. Even wildlife appreciates some negative space - some openness allows them to see predators, while they enjoy the sweet blooms of a favorite plant.
Where I live, roadrunners (correcaminos or paisanos in local Spanish) often hide and pick off hummingbirds as they feed.
So, use negative space - a good thing for all who are in our gardens.