Story wise, an interesting post-Apoc world would be something like this... ecological disasters are being rigged and destroying land and people in the quest to reclaim what was taken and lost. This is due to the machinations of a small oligarchy of Ancient Aliens that wish to restart the world with their guiding hand bringing destruction. And due to the rise of natural disasters and constant weather/climate changes... the remaining humans who got lucky and were spared find their bodies evolving to survive.
Tougher Skin, Longer Endurance, Bigger Lung Capacity, Better Eyesight, etc but no superpowers as we know, just enhanced humans... like Steve Rogers. No only do the humans adapt but so do the animals that survived, becoming bigger, badder, and meaner, and smarter. And the small oligarchy leave some settlers behind to enforce the rules of the oligarchy and to see if Civilization can become what it once was. In the new world of limited technology and dependence on the old way of life.