My understanding has been that Rousseau wanted to reject the notion of isolated individuals comprising a "State of Nature," as envisioned by Hobbes and Locke, as a starting point for arriving at the organizing principle of civilization. Instead, he recognized the social nature of human beings.

Historically, for non-civilized peoples the societal ethos has been 'one for all and all for one'. I see R.'s concept of a "general will" as a muddled attempt at arriving at such a governing ethos. (I might be guilty of reading too much of my own thinking into R.'s motivations and intentions.)

That very ethos did effectively become the governing ethos of Marx's communism, but Marx's philosophical paradigm hasn't exactly worked out. I think the closest civilization can get to that is to recognize mutual respect as the ethic of justice.