Why would social darwinism want to apply the theory of evolution to human institutions?

Social Darwinism seeks to apply the theory of evolution to human institutions by proposing that natural selection should also operate in societal structures, leading to the survival of the fittest. Proponents believe that this approach could justify practices such as competition, inequality, and Imperialism as natural and necessary for progress. However, this perspective has been widely criticized for its disregard of ethical considerations and the potential for justifying harmful behaviors.