In the future, a globalized economy gradually stitches the various governments of the world together into a single federation. The richest and most powerful of each state and economy entrench their economic and political dominance to the point where social mobility has stopped completely, creating a permanent upper-class and under-class, much like the nobility and peasantry of the European Middle Ages.
Technology has progressed to a point where the vast majority of material production is done by robots, entirely owned by the ruling class, which perform nearly every task from resource extraction to transportation to manufacturing and in many cases, automated interfaces sell the goods themselves (Amazon?). The only thing regular people are good for are as consumers, or sources of entertainment. There may also be a gladiatorial system (Hunger Games?) which weeds out the weak and exposes the strong, either to target them as potential threats later, or to have their genetic material used to strengthen the elite gene pool.
Likewise, the militaries of the various nation-states have also been gradually disarmed (as in a global government, there is no war, only rebellion), and replaced with robotic soldiers, completely controlled by officers of the ruling class, who are groomed to lead from an early age, somewhat like the ancient Spartans and/or the Kshatriya/warrior class from the Hindu varna system. Therefore, there is very little association between the military leaders and the underclass, and there is almost no reason at all to disrupt their position of extraordinary privilege.
How would the future underclass rebel, undermine, or otherwise dismantle a system of pseudo-slavery?
To sum up the conditions:
- The general populace has no combat training, nor do they own weapons
- The military is staffed by robots and led by elites who like the way things are.
- The elites do not depend on the underclass for any material needs whatsoever.
- The underclass has little to no access to the backbone of society, such as power generation, natural resources, infrastructure, and so on.
- Any armed rebellion would be swiftly put down with heavy casualties to the underclass and little to no loss of life for the elites.