Lukas Mathis writes about our fear of empty space in visual design in Horror Vacui:

There’s a concept in visual art called horror vacui, or «fear of empty spaces.» It’s the natural tendency of humans to fill empty spaces with stuff. Your new shelf has some empty panels? Put something in there! Your flat has an empty corner? Buy a chair! Or a plant! Something! Anything!

Humans have the same tendency when it comes to visual design. No empty space! Your screen has a few white pixels? What feature can we put there! Quick! Find something we can put there!

There’s a problem with that, though. Empty space is not useless.

He goes on to explain that “emptiness equates to prestige.” In short, don’t fear the empty space!