Photography is all about understanding light and creating depth to your photos.
In the absence of good light, the photo may appear dull or without interest (2 dimensional). Sometimes you can wait for a good light to find it's ways through the clouds and sometimes you have to take the shot.
Furthermore, light has direction. The WOW photos are usually taken during the golden / blue hours just few hours before and after sunrise and sunset when the light is at its best.
Luckily, Lightroom has a solution to that but first you need to analyze the photo, the quality of light, light temperature and direction and the rest is easy; simple keystrokes of the adjustment brush. Just select the local adjustment brush and increase the exposure slider a notch (say +0.5) and draw some strokes starting from the boundaries of the subject where light is hitting. See examples below and enjoy this tip.