Do you also think that God didn't create the universe for us?

If the vastness of universe is for him to prove that he's really powerful, merely the sun and the earth would be enough. They're big enough already. And the universe has always been there, so it wasn't created for us. Adam and Eve were only banished to Earth. If this very universe is going to be used for God's future creations, it's too big for that purpose, because a lot of space is wasted and there's no sign of aliens for a few thousand light years, so what's the universe for? The stars and the darkness?