Generally these films/stories don’t do a great job of world building in my experience. If there has been a global disaster that has killed off lots of people, the economic and materialist reality would be highly cooperative.

Humans are highly pro-social, and the ‘kill to survive’ foundation of the storytelling just seems overly grimdark. Competitive warlording is a terrible way to run a society.

There’s this impulse to make the stories conform to a feudalist to frontier continuum that seems to be pretty shallow. I guess it makes it easy to rely on dramatic tropes from legacy media though.

One exception to this might be On The Beach iirc. Most of the plot involves the characters venturing out into the apocalyptic world because there might be other survivors sending out signals. But the social structure of the enclave the characters live in seems mostly pretty chill from what I recall. Not really any major human conflict in the story.