What's the use of stars assimilating population?

Used to describe the conflict and integration between alien civilization and human civilization. In sci-fi works, the story of stars assimilating population is often discussed by writers about the identity of human culture and identity, as well as the influence of foreign culture on human beings. The assimilation of population by stars can also be used to express concern and appeal for human cultural diversity, emphasizing that everyone should maintain their own uniqueness and individuality. The assimilation of the planet to the population means that in science fiction works, an alien assimilates human beings into his own race through technical means, making human beings lose their own characteristics and culture and become a part of aliens.