The universe does not have empty spaces or voids. It is full of energy. Energy has mass. Mass creates gravity. Gravity keeps the universe in perpetual motion. Motion creates vibrations and vibrations create energy. Mass, gravity, motion, and energy make a singularity called randomness.
Without energy, there is no humanity. We exist because of energy. Energy sustains us.
Since primitive times humans needed energy. Sustenance gave us energy to survive and build our shelters. Energy provided us with the much needed heat to sustain the colder seasons. Energy made our food taste better. Fire is energy.