the reason zizek initially became famous is because he made the connection between freud-lacan and marx in a similar way actually. he said, well, look, surplus-enjoyment works the same way as surplus-value. like libidinal flows worked like capitalist flows.
i think freud is a strange sort of surrogate for marx in a lot of well known post structuralist texts. like the whinging authors couldn't directly address the system without getting labelled as reactionary. that or its some sort of stockholm syndrome and they are like battered handwringing wives to marxism's drunken husband who comes home and beats them on fridays but they "still love him" inexplicably