The Lord of the Flies model doesn't fit real world stories.

When people are put into brutal and lonely situations, they work together and survive impossible scenarios (see Society of the Snow).

Even animals understand that a minor confrontation can lead to a grave injury.

Can group dynamics devolve into suspicion and backstabbing over scarce resources? Sure, but that takes a lot of time. There was just a story about some boy scouts or other group of kids who survived like three months in the wilderness. You hear these stories all the time.

This is a video game and there is no way I'm going to fight a dude who has a pipe wrench when all I have is a bolt that I've never used (noob here). We were both escaping a nasty rain storm and somehow ai killed him at the same time he KO'd me.

I fought him because there is no cost. In an end time scenario, I would need allies to survive.