Epistemic status: don't take it seriously
In a post apocalyptic setting, the world would be run by the socially skilled and the well connected, with corruption and nepotism ruling.
I say that at the start, because I've been trying to analyse the attraction of post-apocalyptic settings: why do we like them so much? Apart from the romanticism of old ruins, four things seem to stand out:
- Competence rewarded: the strong and the competent are the ones ruling, or at least making things happen. That must be the case, or else how could humans survive the new situation, where all luxuries are gone?
- Clear conflict: all the heroes are in it together, against some clear menace (evil tribe or leader, zombies, or just the apocalypse itself).
- Large freedom of action: instead of fitting into narrow jobs and following set bureaucratic procedures, always being careful to be polite, and so on, the heroes can let loose and do anything as long as it helps their goal.
- Moral lesson: the apocalypse happened because of some failing of past humans, and everyone agrees what they did wrong. "If only we'd listened to [X]!!"
(Some of these also explain the attraction of past "golden ages".)
And I can feel the draw of all of those things! There a definite purity and attractiveness to them. Unfortunately, in a real post-apocalyptic setting, almost all of them would be false. For most of them, we're much closer to the ideal today than we would be in a post-apocalyptic world.
First of all, nepotism, corruption, and politics. The human brain is essentially designed for tribal politics, above all else. Tracking who's doing well, who's not, what coalition to join, who to repudiate, who to flatter, and so on - that's basically why our brains got so large. Tribal societies are riven with that kind of jostling and politics. We now live in an era where a lot of us have the luxury of ignoring politics at least some of the time. That luxury would be gone after an apocalypse; with no formal bureaucratic structures in place, our survival would depend on who we got along with, and who we pissed off. Competence might get rewarded - or it might get you singled out and ostracised (and ostracised = dead, in most societies). Influential groups and families would rule the roost, and most of the conflict would be internal. Forget redressing any injustice you'd be victim of; if you're not popular, you'll never have a chance.
As for the large freedom of action: that kinda depends on whether we go back to a tribal society, or a more agriculture-empire one. In both cases, we'd have less freedom in most ways than now (see above on the need for constantly playing the game of politics). But tribal societies do sometimes offer a degree of freedom and equality, in some ways beyond what we have today. But, unfortunately, the agriculture-empire groups will crush the tribes, relegating them to the edges and less productive areas (as has happened historically). This will be even more the case than historically; those empires will be the best placed to make use of the remnants of modern technology. And agriculture-empires are very repressive; any criticism of leaders could and would be met with death or torture.
Finally, forget about moral lessons. We're not doing enough today to combat; eg, pandemics. But we are doing a lot more than nothing. So the moral lesson of a mass pandemic would be "do more of what the ancients were already doing, but do it more and better". Same goes for most risks that threaten humanity today; it's not that we fail to address them, it's that we fail to address them enough. Or suppose that it's a nuclear war that gets us; then the moral would be "we did too little against nuclear war, while doing too much for pandemics!"; if the dice fall the other way round, we'd get the opposite lesson.
In fact, there would be little moral lesson from our perspective; the post-apocalyptic people would be focused on their own ideologies and moralities, with the pre-apocalyptic world being mentioned only if it made a point relevant to those.
All in all, a post-apocalyptic world would be awful, and not just for the whole dying and ruin reasons, but just for living in the terrible and unequal societies it would produce.