We cannot overemphasize the difference light makes to photography. Photographers have to learn to read light and know what kind of light is best for which kind of photography. Then we shoot the right topic in the right light for that topic to create the image we want. Have a look at the next image:

The light is already turning warmer (red and yellows) and there is detail in the shadows. This shot is certainly better than shooting the same scene in the middle of the day in harsh light. The light in this image is till harsh(ish) to me. Now let's wait for the light to get softer. Let's wait for the shadows to change ...

This shot is of the same scene (Thor's Hammer, Bryce Canyon, Utah). We simply waited for the sun to set, but did not wait too long for it to get darker. Compare the mood of each shot. Compare the light in each shot. What you are seeing is a comparison between harsh(ish) light and soft light. Look at the shadows in the first image and compare them to the rock face in the second image. Which image do you prefer (light-wise; forget the composition)?

          Harsh light generally is not pleasing in landscape shots. Soft light just presents a different mood, a different look. In post processing we can boost contrast a lot more with soft light than we can with harsh light.

          Learn to read the light. Wait for softer light (depending on your topic). By all means, shoot even after the sun has set. Very few people like harsh dark shadows in landscape images. Soft light seems to even things out. Usually the background light in the sky is also better just after sunset. If the soft light is due to overcast conditions it may be better not to include the sky in the shot.

          Happy shooting,