Tough question. Some people prefer to play against themselves so it can't always be said it's the competition that drives us all.
I guess we love to create and destroy, and chess facilitates this urge beautifully. Dark and light, up and down, make and break (shake and bake 😁), positive and negative and electricity, neuron left and neuron right and don't forget the neon lights.
Chess was made in our nature, that's why we love it.
Thanks