I saw a video in which some characters of the Fallout tv show open a fridge and find an alien and just toss it out because they want the working fridge. I’ve never understood (or really bothered with) why Fallout had the nuclear “event” which triggered the use of the shelters. Was it an alien invasion?
more or less
they underestimated how much life would survive on the surface; they couldn’t have predicted the Forced Evolutionary Virus; the Enclave (US rump state) is too fractured and horrifically incompetent to reënact Manifest Destiny; and most of the vault experiments failed catastrophically (if they weren’t cut short by mechanical failures, deliberately or not).