Landscape mode is used for a large depth of field. It allows everything in the photo to be left in focus.
This is a landscape shot that also expresses balance. All objects in the scene are in focus. The horizontal rods, the two fences, and the buildings and trees are all in asymmetrical balance.
This is a much more asymmetrical landscape scene, yet it still expresses balance between the buildings on the left and right. And again, everything is left in focus.