White supremacy is comparative, not intraracial (within the same race). In a completely white society, the white man will continue to be trampled on, will continue to be humiliated, and the same hupergamics and labor dynamics will exist that have always existed in a system of capital accumulation. Thus, they will be able to call for war, expand, create authentic genocides to alleviate the lack of jobs, opportunities, and perhaps the frustration of not having a pussy. The surplus of men would be cleaned up with bloody wars and thus, the cycle would continue.
Notice, then, that man, like no man, is perfect. Just a more developed race, not infallible. They will be able to kill every Jew on the face of the earth, and create an ethnostate as pure as possible that without the rational and interventionist management of morality and the effective restriction on women, The white man will continue to suffer, and doubly so, because capitalism will consume him and, undoubtedly, the majority will not be able to prosper.
By comparison, of course, the white man lives better and has better conditions than in the societies of the rest of the planet, and that does not necessarily make him happy, because the material will never replace the hunger for harmony that is only possible with an ordering ideology: a purpose of security and maximization of life.
Who wants freedom when there is no security?