Fall of Rome, a long running process that for the outskirts of the empire meant people lived and were fed better based on the increased bone density of their remains.

So we have a metric of resources you need to keep people under control vs resources you would need to release to people if you did not control them. This number is currently very low through automation, fake news optimisation etc.

So elites get all the resources secondly they give out to affiliates (Roman's debts forgiven, discount wheat for Romans, land to 75k Romans) then it becomes unsustainable because it has giveaways have no solid economic foundation, then affiliates become strong, then make everyone Roman so as to dilute power and then the former affiliated secondary elites stop helping and/or revolt and through their organizational capability also everybody else joins them, sometimes through unrelated incidents. But Rome has already fallen years ago, and after the actual rubber stamp, most people except those at the center of empire are better off. What is missed, is products of economies of scale, but people have already learnt to hate them along the insurmountable accompanying taxes.