Ranking the immortal sects, opening up the sect, and educating the cultivators was a path Chen jingzhai had designed for the immortals at the bottom. It was a win-win situation.
The more worlds they submitted to, the more immortal cities they had to manage, and the more heavenly soldiers and generals there would be. It would solve the problem of Immortals and provide a way to rise, so why not?
The eight desolate world could absorb and release connate Qi, which meant that there was no need to worry about the lack of vitality in the future. This was the greatest advantage.
According to senior brother floating cloud's information, the vital Qi in the outside world was not as rich as that of the eight desolate world. It was just of a higher quality.
Why did the void Dao sect want to harvest the origin power of the Qianyuan realm? Other than refining treasures, its greatest use was to let spirit veins devour it.