Hebrews 2:5-18 has this logic: God has subjected the disobedient and dying world to the True Man (5-9) AND God has united us to the True Man so that He delivers us from lifelong subjection to disobedience and death. (10-18) This talk only deals with 5-9.
As regards the first point, we see that God subjected all things to humanity but we failed miserably. This is why we don't see everything in subect to him, but instead we see a different 'Him' i.e. we don't look to ourselves, but to Him who was subjected to death and now risen and reigning in glory forever: Jesus.
We also see how special a human being is. God is mindful of human beings and He cares for them. The context for every human being is the mind of God, and God's care.
To know what a True human being is supposed to be, we must look not at ourselves, but 'see Him' - Jesus. But Jesus is not just a model human being, He also did something for us. He became subject to death in order to deliver us who are in slavery to death and decay.
