Societies get larger and more interconnected, so there's always a comparatively small ruling class and an increasingly larger subjugated class. Zero sum end-gam

Societies get larger and more interconnected, so there's always a comparatively small ruling class and an increasingly larger subjugated class. Zero sum end-game: the subjugated class comprise the entire world. (I'm not sure I actually believe this can happen.) Also, there isn't always a determined individual or cadre that decides on a goal of total domination. There are structural societal issues that tend to progress in one direction. It's politically harder to repeal laws that were put in place for reasons of "security" and were built on fear. Not always, but often. This tends to secure power in the hands of the few, over an expanding swathe of the public.