Design is a very ancient practice, but graphic design really found its core principles post World War One. Games are also very ancient but video games are still finding their feet. I think graphic design has a few things to teach people who make games, so here are the big concepts every graphic designer learns. You should learn them too!
First, studying graphic design is about building the skill to see things other people just accept. More importantly, it’s learning to see and name things ordinary people just are annoyed or repulsed by but can’t say why. You can’t just read about it, you have to look at many examples and practice making them. Over time your eye and hand become smarter. Good graphic design makes games more trusted (increase sales) and more pleasurable to play (NPS) and when done right, fades into the background so players can focus on the game (higher DAU/MAU.)