this is mostly related to what is brought up in Origin of Family. Class society was historically progressive due to the evolution in generalized commodity production, however, it also brought about a contradiction of private accumulation. I bring up this being related because primitive societies lived as a community with a matrilineal framework, and the contradiction of private accumulation (origin of private property), coincides with the first class division, that between man and woman, which starts the eventual alienation of the working class from their labour, from others, and effectively from themselves.
"In an old unpublished manuscript written by Marx and myself in 1846 I find the words: “The first division of labour is that between man and woman for the propagation of children.” And today I can add: The first class antagonism that appears in history coincides with the development of the antagonism between man and woman in monogamous marriage, and the first class oppression coincides with that of the female sex by the male. Monogamous marriage was a great historical step forward; nevertheless, together with slavery and private wealth, it opened the epoch that has lasted until today in which every step forward is also relatively a step backward, in which prosperity and development for some is won through the misery and frustration of others."
you're confusing socialism for social democracy. social democracy comes at the expense of large scale exploitation of the third world through neo-colonial imperialism, so it is still capitalism