The Chaos World is none other than the stage of Pangu Great God's Tao demonstration, and at the same time, it is the very meaning of the Prehistoric World's existence.
And now, as the Chaos World is on the brink of destruction by the hands of the Chaos Demigod, this implies that the Prehistoric World has lost its intended purpose. As such, there's no longer any necessity for its existence.
After Pangu Great God's revival, he destroyed the Chaos World he had created with his supreme Divine Abilities, resetting everything back to zero.
In an instant, Heaven and Earth shattered, all things returned to Chaos, and within that world, not a single living being managed to escape.
Even the lofty Saints and the Daluo Jinxian of the Primordial who transcended Heaven and Earth could not evade the fate of becoming nothingness.