Fantasy Dragon Realm

Long before the ancient apes climbed down from the trees, dragons were soaring in the sky. They were powerful and long-lived and were the apex of the world's creatures. However, I don't know when, the dragons gradually became rarer, and the earth became a human world. They found wonderful power from their own bodies, and out of their yearning for dragons, they also named this power after the dragon. The world begins with chaos and will end with chaos. How far can this power support mankind?