I didn’t say that a system existed that prevented all wars, genocides, and famines, I don’t know where you got that from.

No, capitalism has not existed since the first civilization. You’re making the common mistake of conflating capitalism with a market. Capitalism is the system of private ownership that separates the working class, those who make money by selling labor, from the owning class, those who make money by owning the means of production. Prior to around the 16 or 17-hundreds, it did not exist, and before then most of the countries where it originated were some variation of a feudal society.

But you’re kinda right with the Soviet Union thing. The Soviet Union was not capitalist in the same way a place like the United States is, but it was very similar. The key difference being that the owning class was united with the state, which allowed capitalist and state oppression to unite a lot more dramatically.