There are a lot of popular themes in post-apocalyptic storytelling that you see over and over: "War never changes," "People are the real monsters," "Man's hubris will be our undoing," "Civilization is defined by people, not laws," etc.
I think a theme we need to explore more in times like ours is "Nobody is coming to save you."
It's up to us. We can't sit and wait for a hero to swoop in and save the day. We each have a part to play, and every little thing helps.
All we have is each other.