Capitalism is not about individuals being greedy. Calling capitalists greedy is like calling fish greedy for needing water. The capitalist system requires constant profit maximization to prevent firms from crumbling, the capitalists are tasked with ensuring this, generally by (at first) maximizing exchange value of their product and minimizing costs (usually labor), then later using monopoly position to charge economic rent. In the heart of empire, financialization has meant trying to skip the first step via large financial investment up front, like with tech monopolies. The system itself forces exploitation, dispossession, colonialism, and ultimately crisis and war.

Historical empires conquered for reasons we often don’t really know specifically, as the accounts we have are written by victors with limited access and understanding. But ancient peoples were just as sophisticated as us and subject to material forces as us, so it was certainly not just being greedy. The economic base can force hands, for example. The Roman slave and debt system was unsustainable and required debt jubilees and war and invasions to be maintained, for example. For the ruling class of Rome, was maintaining the empire only greed or was it what they were taught to do as the moral and right thing?