More than just being melodramatically artsy, black and white photos eliminate the harshness of digital color noise and make it look more like film grain.
Poor white balance and grainy image makes this photo tricky to fix in color
It also removes worries about white balance or skin tones, and you can mess with exposure a good deal more before an image degrades past being acceptable.
Converting to greyscale removes the color and grain problem, and emphasizes textures and lines instead
Even if you don’t go full black and white, de-saturating your images slightly can also help them approximate how our eyes see in low light, when our eyes are less sensitive to color.