In the beginning, God created the heavens and the earth. Why? What did He gain?
You need an accurate standard and starting point before taking any measurement. That is what baselines and anchor points are. They are a framework within which we see objective reality. We focus on what the framework includes.
In the Transfiguration story Jesus is seen by Peter, glorified and talking with Moses and Elijah. Peter’s point of view included three glorified beings and he was overwhelmed. How to choose among them? You don’t! Instead, honor them all alike!
But Peter’s baseline was not God’s baseline. As He immediately made clear, there was only One Person that God wished anyone to give attention to.
There are plenty of indications that God enjoys the presence and love of His children. But He wishes that love to be unforced and free. And that free choice on our part can only be demonstrated if there is an alternative – a competitor, as it were – for our attention.
I suggest this is a reason God made a material world for us to stand in. It is there to present an alternative focus for our senses and sense of judgement. Eve thought the “apple” looked good enough to her and that was good enough reason to trust her own judgement rather than God. Following a similar baseline of personal judgement, her first son killed his brother.
The Creation that surrounds us and appeals to us on every natural, sensual level, is there so that we can exhibit a free choice. The host of Heaven watch to see whether we think the Author and Finisher is more worthy of our love than the ephemeral satisfactions of a moment. They watch to see the baseline we will choose: His or ours.