Even here, the concept is decaying. Accountability, as explained elsewhere on the thread, is about being asked to explain and justify your actions. If a poor person gets arrested and shows up to court, frequently nobody listens to their explanation. The mere fact that they're poor and in court is evidence of guilt. That's not accountability; that's just punishment.
Accountability requires a common standard of conduct. People have to agree on what the rules are. If they can't even do that, the concept ceases to have meaning, and you simply have the exercise of power and "might makes right".
From what I recall of history even the most bloodthirsty warlords somehow got reliable systems of accountability up and running from their princes/serfs/merchants/etc… at least long enough to maintain sizable empires for several generations.
It’s not like they were 24/7 in a state of rebellion.
It comes from having a dominant ("hegemonic") discourse - basically the set of values, mores, opinions, etc. that are allowed to be aired in public. A consistent Overton window throughout the population, basically.
Periods in history like now (or the late-1920s/1930s, or the 1850s-1860s, or the mid-1600s) are ones where there is ambiguity in power structures. You have multiple competing ideologies, each of which thinks they are more powerful than the others. Society devolves into a state of anomie, where there's no point following the rules of society because there are multiple competing sets of rules for society.
The usual result is war, often widespread, because the multiple competing value systems cannot compromise and so resort to exterminating the opposing viewpoint to ensure their dominance. Then the victors write the histories, talk about their glorious victory and about how the rebels threatened society but the threat was waved off, and institute a new set of values that everyone in the society must live by. Then you can get accountability, because there is widespread agreement on the code of conduct and acceptable set of justifications for the populace at large to judge people by.
