@ junco ... it CAN ... but .... A garden, per se, can be a random collection of plants that need no justification for their being included in a garden other than that their owner wants them. A landscape is a highly specialized garden in which the plants are usually part of a larger structure of plants, and specific demands are made on their abilities (to screen, produce shade, avoid looking bad, be maintainable at certain sizes, be permanent, etc.) In a non-landscape garden, very frequently the number one criteria for plant selection is its flowers. In a landscape garden, that is often the last criteria to justify selection. If one is buying plants and asking where they can be planted, that is likely gardening. If one has a place for a plant and is asking what plant will best work in that position, that is likely landscaping. A garden CAN be an adornment for a home, but it requires that one be more discriminating about what plants are chosen and where they are placed. Sometimes it can be very charming, but on the other hand it sometimes comes with higher maintenance. MOST people do not want to put forth the effort so gardens, per se, usually only work out well for a small percentage of people.

One must love the vagaries of landscape terminology, where often words don't have very exact meanings. In general, a groundcover is any number of plants that are capable of solidly covering the ground surface but where their growth height has a finite, usually low, limit. Often they are plants that spread sideways. Sometimes they are vines grown on the ground like Vinca, and sometimes they are clumping plants, like Liriope. In terms of residential yards, a groundcover might get as high as 3' (my own guidelines). But one chooses its height based on all the factors that apply in a given situation: window height, overall size of space, particular purpose, necessity for pedestrian traffic, etc. Grass turf is usually not considered to be a groundcover per se, even though it is low and covers the ground solid, because it is highly specialized, needing to be pruned weekly by machines. Most groundcovers are not meant to be walked on but can tolerate varying degrees of it. It seems to me that your alcove could accept a height of 6" to 18" (the taller so long as one needed only rarely to walk into the area.) But that depends on your relocating the hose spigot to somewhere more convenient. (If it's the pipe coming out of the ground, it shouldn't be too difficult. If it's running through the wall it will be more involved.) If 'Big Blue' Liriope grows where you live, it could be nice there. If you have to leave the hose spigot, you'd need stepping stones or a walk, and a way to guide the hose. And a wall mounted reel. Still, seems very inconvenient in that location. At the strip along the garage, the same Liriope would work well there, too, IF it grows well there. But it would be nice to see annuals below the windows that come up higher, to the bottom of the window. In the picture above, it looks like Liriope spicata between wall and walk, which isn't going to be as pretty or interesting as L. muscari 'Big Blue'.

Garage rental unit with all the associated engineering headaches will start at 500K CA pricing for something small. Just because the lot is zoned for it doesn’t mean it will be easy or cheap. 200K in landscaping doesn’t go far on a giant slope either. But 700K will get you a bare minimum for what you are wanting. It only goes up from there. It could easily be more than 1M yo create the luxury estate like presence that you seem to want. If you want to move out out of CA, you could probably do it for 200K in a lesser metro FL area. And still have tropical plants. But more water for them.

I agree, the bushes hid the house and there is nothing there that needs hiding . . . think of your landscape like nice jewelry instead. I agree about taking photos to a good local landscape nursery. They can help you. And yes, less is more. Classic landscape design is to plant in odd numbered drifts. Three or five. Or one gorgeous specimen plant. You have many to choose from. I have a flowering crab, flowering dogwood and star magnolia in my front yard. Any of those would be gorgeous choices . . . I have an allee, you don't need all three like me, just giving you some ideas on a specimen plant. Or a gorgeous weeping evergreen or some of the dwarf ones. We had globe arborvitae and mugo pines in our front yard. Some kind of juniper too, but I am going to have to tear those out, they got way too big. Look for dwarf varieties that don't need pruning to keep in line. I got ideas of looks I liked by perusing magazines and books at the library and googling stuff online. Some of the better nurseries will also have demonstration areas where you can get ideas too.