"If it's just us, seems like an awful waste of space."
This statement was repeated thrice in the movie Contact (1997). I have heard many skeptics and doubters use the same sentiments. You can repeat this statement as many times as you want and it will never make the words true. The fact is, there is only just us in the universe. If there was not, that creates a massive problem. Scripture says that we are made in God's image. In whose image would other races be made in? Scripture says Jesus was born of a virgin, lived a sinless life, died on a cross for the sins of His people, rose from the dead on the third day, and ascended into Heaven to sit at the right hand of God the Father. That means that any other races that might exist are condemned directly to Hell. Unless of course every one of these others races are somehow sinless.
With just us in the universe, the size of the universe is not a waste of space. Everything exists for one reason and for one reason only; to glorify God. Our oceans are largely unexplored. Are you going to say that since our oceans are largely unexplored and we do not know what is in their depths that whatever might exist down there is just a waste? Even if we never see everything the oceans contain, it is still not a waste. Maybe in our ignorance we might presume it to be, but not to God's wisdom. Everything exists for His glory. Every galaxy and the beauty of their solar systems, suns, stars, planets, moons, etc., whether we ever see them or not, were created for the glory of God.
Two truths exist simultaneously. The first truth is that while our egos think we are the best thing to come along since sliced bread, in the grand scheme of things and considered in the big picture of the entire universe, our existence is insignificant. We are but a speck of dust in the ocean that is the universe. The second truth is that while compared to the expanse of the universe and all it contains, we are insignificant, nevertheless we are the pinnacle of God's creation. We are unique. We were created in His image. We have a soul. We have consciousness. We can consider ourselves and our existence. Animals do not contemplate the meaning of their existence. They do not consider what they might do, how they might do it, or what the ramifications might be. Animals only possess instinct. The way animals function is like technology. There will never be such a thing as autonomous artificial intelligence. A.I. is only capable of doing what we program it to do. It will never be able to have an individual thought of its own. Animals function in the way they were created.
Humans are not animals. Some of us act like animals because we have been told we are animals for a long time, but humans are above every animal God created. Animals are not created in the image of God. They cannot reason. They cannot think. They cannot marvel at things in creation. Everything we take for granted about ourselves is an element that imitates an attribute of God's character. For further examination of this, see Created In the Image of God and Triune Being. Everything in this universe was created to point toward God.
"For by Him all things were created, both in the heavens and on earth, visible
and invisible, whether thrones or dominions or rulers or authorities--all things
have been created through Him and for Him." Colossians 1:16