The very supposition of God’s sovereignty relies on the false presumption that God exists as part of reality (which ancient pagan religions believed). Accordingly, the question concerns how the rest of reality would function without God’s supreme direction.
Christians do not believe that God exists as part of reality or that God is the most powerful (sovereign) part of reality. Rather, Christians believe that reality itself exists as an expression of God’s creative divine intention. As St. Paul says in his letter to the Colossians (1:17), “He is before all things, and in Him all things hold together.
We exist because of the continuous act of God’s creative power. Without the divine intention to create us, or to sustain us in being, neither we nor the world (or universe) would exist at all. We would miss nothing because there would be nothing to miss and no one to miss it.