From a narrative standpoint I get it. Have a ton of mystery and have the player uncover it piece by piece as the narrative goes, but you know what? I'm sick of this trope. One of my favorite aspects of the world building in BioShock Infinite was that you were apart of that world going into complete shit. Or the Resident Evil series slowly getting worse and worse (in terms of the outbreak) as games progress. I like being apart of the fall of society. Half-Life being just a routine day on the job and suddenly having your whole world turn up side down I feel is way more relatable than the game dropping you 10 years after shit went down. I feel like too many games we are just thrust into the action and basically told "we don't have any time to explain, take this gun!". Halo, Gears of War, Doom, Fallout. The Last of Us starts off so strong, with the confusion of this strange illness, emergency services failing, this small town going into complete chaos, and then bam, time skip. That premise was so great and I really wanted a survival horror in the moment of a zombie outbreak, but it just doesn't deliver.