Rheingold seems to me a caricature on capitalism, even without Patrice Chereau's production. Three rich heiresses (old money) **** off they fortune. A group of rascals struggles for it among themselves. There are high burgoisie mixed with aristocracy headed by an alpha-male with spear and their inimical neighbors, skilled in building. There is bourgeoisie of lower social strata, but even more aggressive and unscrupulous, their primary business was metall industry. He layed hold of the gold even without marital gambling. At last, a lawyer - busyness executive - broker, whatever you like, who helped first group and wasn't destroyed in the act. Fire is his advertising identity. Did Ayn Rand like Wagner?
Following operas are rather psychoanalytic than evidently sociological. But this theme appears again in Götterdämmerung.