Clearly, demons were keen about creating their own clones for a reason.
In order to satisfy the ever-increasing demand of magic power growth, demons needed to devour more souls. Although the Abyss could connect to the Infinite Worlds, demons could only enter one world at a time with their main bodies. Even if they tried their hardest to obtain souls, they might not be able to get too many at a time. The hatred and vigilance against demons by the various races in the Infinite Worlds, the obstruction of angels, competition among the same race, etc. greatly negatively affected the demons' plans to devour souls.