Even if a Seed World, fresh out of the World Forge, could not compare to an Empyrean World, that did not mean it was worthless. Every world carried trillions of life forms and countless resources. While these might not be of great value to those at the Third Realm or even powerful Divine Transcendence life forms, they were still useful. A large quantity of these resources could be traded, making new worlds a target for powerful forces whenever they emerged.
If the native life forms of the new world were fortunate, they might encounter powerhouses from their own race who were honorable and would not exploit them, or at least not too much. But there were also instances where their luck ran out, and they were taken over by a group of maniacs who would slaughter everyone and plunder every resource.