Generally speaking, empires are negative entities. The work because they took advantage of being first (or first to be successful) and used that advantage to absorb the wealth of those they conquer. While a lot of productive things can come out of such an environment, at its heart the empire is sustained by consumption. When there is less to conquer, there is less wealth available for the wealthy, but the desires of the powerful is to always increase. The wealthy use power to to start pulling wealth from the empire. The common identity of the empire is destroyed and the wealth is no longer available to defend the empire, so the empire is ultimately absorbed by the next identity that comes along.
Wealth isn't some finite quantity that is merely taken or traded between a group of individuals. This is highly ignorant of economics and is a worldview that sadly what drives a lot of hysteria around wealth inequality (that when one person has more wealth it means they deprived it from another person who would have had it otherwise, combined with the idea it just sits there in a bank account not being used or it's all being spent like a consumer).
It is not a given that massive wealth accumulation involves depriving others of wealth but it's also very often the case.
While it's ridiculous to view wealth as a finite thing, it's just as ridiculous to imply hysteria over wealth inequality is based in ignorance. There is a long-standing trend of capitalists treating lower classes as exploitable resources undeserving of the means to have a healthy and happy existence beyond what keeps them productive inside the constraints of the current system.
Median salaries haven't been stagnant while the rich get richer because that's what's best for everyone, it's because that's what's best for the people with control.
Just for the record, many people who oppose and criticise massive wealth inequality are fully aware of the basics of economics (or even advanced economics).
