Landscapes tend to have most perceived depth if three main elements (fore-, middle- and background) compete for the viewer's attention. That makes the eye travel back and forth inside the composition and thereby a highly static impression is alleviated. If we remove one of the three, the image is much easier perceived as flattened unless contrasting colours come to the rescue...
The hackneyed version of a landscape is shooting with a very wide angle up close to some object of a known, small size to make it appear "dramatic" and in the process, by needing to move in close, the middle- and background lose a lot of their impact and scale. Even high mountains become just wiggles in the horizon.