ETA: The following was all in Ohio btw, not CA.
Ground hunting was the only way I hunted during the limited time I hunted as a teenager over 10 years ago with a compound bow.
I didn't really know what I was doing, but I had a tip for a good place in the thick brush/reeds of a marshy lake edge. I wasn't familiar with the area, so I would sit in the snow at the base of a tree, from dawn till dusk, and eat a sandwich in place, where I was.
Problem was, the deer would always show up too close to take a shot at. I literally had a deer close enough I could kick, but my bow was leaning against the tree.
I also still hunted in the back 40 where there was always deer sign, but I never came across a deer in our woods, ever. I was more familiar with our property, but I still didn't know what I was doing hunting wise.
I guess what I'm saying is that yes, sitting in front of a tree can work, it did for me. At least, I was able to go unnoticed with deer around, but I've just never been a good hunter I guess.