At that level you might as well argue that WWI was caused by agriculture, because without agriculture the war would not have happened. Any history without aristocracy or monied interests would be likewise completely unrecognizable. But neither social nor economic inequality plays any significant part in any credible narrative on the causes of the war that I've read. (And I've read many).

You are attempting to make assertions in high causal density situations; the evidence supports an infinite number of conclusions, and yours are not particularly convincing.