The Dragon in the World of Cultivation

In 3864, the human world evolved again from the technological era to the cultivation of immortality by all people. However, even though cultivation brought great convenience to people, people's desires were too strong. In 3920, the "Tide of Vientiane" was launched for their own benefit. Tiandao discovered that human beings have the power to After suffering a terrible amount of terror, he chose to take back people's power, but the evil devil would not give up, so he chose to use the "Tiandao Campaign" held every hundred years to select the best people to continue to protect the peace of the earth, but he was unwilling to possess this power. Why on earth is this?