Any story that follows the monomyth, or Hero’s Journey — as named and made popular by Joseph Campbell and his The Hero with a Thousand Faces — involves a return.
The return is one of the more important parts of a standard hero narrative, since it’s at that point where the hero must not only eschew the place (physical or metaphorical) of where they received enlightenment, but is tasked with gifting that knowledge to the unenlightened. Arguably, bestowing that wisdom upon everyday people in their everyday world is the very thing that makes them heroic.
For example, in the post-apocalyptic short story By the Waters of Babylon — which I’ve referenced before in relation to Made in Abyss — John returns to his father and tribe with important knowledge of the civilization that preceded their own. Although his father cautions him of dumping too much information on the uniformed, the realization that what he thought were gods were actually mere humans who destroyed their own world is what inspires him to say that they must rebuild. His realization and return likely spark a period of growth and industry.
Made in Abyss‘ second episode is also the start of Riko’s journey as the hero of the main narrative, but it also has some fascinating commentary on the return itself, through the structure of the Abyss.