The history of oppression shows us that in fact, there have been complex human societies which did manage to be genuinely egalitarian. There are examples from all over the world, from Aboriginal Australia, to prehistoric Turkey, the Indus Valley and North America before European colonisation. What these examples all have in common is that not only did they not have oppression, they did not have exploitation either. They weren’t class societies.
Muslim nobles subjected most Muslims to a miserable, difficult life of serfdom. Christians from the Byzantine Empire continually tried to convert Muslims to Christianity.
The New Deal helped improve the lives of the suffering people of the depression. The New Deal played an important role in the economic and social affairs of the nation.