I've been thinking about it a lot as simply a literary tool and how hard it must be to come up with all the little notes and logs that just give the audience little glimpses and makes them piece the whole story together themselves, as opposed to simply telling a story in a more traditional way. It always feels like what we, the player, can see in the course of a game is miniscule compared to what they had written behind the scenes.
Haven't played it, but not too long ago I watched a video series on the story which was more or less a playthrough of all the games that exist and holy shit it's got an awesome story, and done way before games of that genre were doing stories of that magnitude.
It made me wish I had actually gotten into Halo's single player because I have to assume it's just as gnarly. I only ever was interested in the MP tho 😅
What is showed me was how believable the beginning of zombie movies and TV shows can be where people don't believe the zombies are real or worse, have never heard of the word zombie.