I just picked three books at random after a ten second search. Pick a topic. Any topic. I guarantee you can find multiple books on how to do it. From smelting iron to forging tools and machinery.
Ok, why not? If your scenario, do you prefer to imagine you starved to death trying to figure it out, or that you were killed so that someone else can have the book?
Either way, smelting iron into swords seems reasonable. You've got a great how-to book that you somehow got out of the city and carried at the expense of extra food/water/clothes/weapons. Got easy steps and pictures, even.
You got another book on the forge? where ARE you getting the material and expertise to build that? Assume you've got a team feeding and protecting you while you experiment? Are we assuming you've got a large chunk of iron hanging around as well, just found it?
Not saying any of this is impossible with time, but that that's not a resource you're going to have available for a while. And that while you may get lucky and find the perfect book, there's a million things underlying it that you ALSO don't have.
Believe it or not, the world managed to thrive for thousands of years prior to the last 50 years of dependency electronics. They also didn't have the things like endless roads or cross-continental railways pre-built to take advantage of their inventions. And you know what else? Much of that knowledge still exists, even if only in books
Know what else they had? Experience having DONE those things. Up until about 100 years ago, you had a couple thousand years of blacksmithing experience, in most cases traceable directly from master to apprentice. And available equipment handy that you could use, learn on, and improve. Without google, where's the nearest foundry to you? People were more self-reliant back then. They HAD to do more themselves (farming, sewing their own clothes, woodworking, fighting, depends on location and era, but good general topics). For the most part, people just don't know how to do much of that themselves anymore. Not really sure how you argue that...
Should this stupid scenario ever come about, people will have the same -- if not more -- motivation to redevelop those old technologies. Especially if they're a maniacal dictator with nearly unlimited resources and a strong desire to gain a tactical advantage over their enemies.
Eventually, with time, yes. Not on a small scale, and not in the short term. Although think the premise you're working on there is silly in that regard.
Despite what you may think, not all people aren't stupid, helpless, or lazy.
Fun strawman, but not what I'm arguing. I DO think people have become dependent on technology, and not nearly as many people know how it works, or how to recreate it themselves anymore. And the infastructure to loot to recreate it has moved past what's useful. If you wanted to loot the wagon shop, could probably get it going again with a little effort. The robotic factory that builds cars is a lost cause without electricity and computers. And the foundry isn't the smith down the road, it's some Terminator 2 monstrosity.
You're almost as bad as those loons on Ancient Aliens who are convinced that aliens built the pyramids because lifting and carrying a stone is hard work. And God forbid someone spend more time doing actual work than fritzing up their hair and sitting in front of a television camera.
Not even trying to hide the strawman on that one, huh? Pyramids were built because they had a massive amount of disposable slave labor, and didn't much care how many died in the process. And they weren't expecting the WalMart to go up in 3 months, it was expected that it take 20-30 years. Given almost unlimited people, funding, and time (and motivation), and voila', pyramid.
We picture it as hard because we can't figure out to build a big enough crane system. They built a ramp, had 10,000 people push, and then if the 10,000 got crushed, tried with 20,000 next time. No aliens required.
Will just ignore your last comment about whether this scenario (honest, god-fearing work) is better or worse than what we're doing today, as I can't see how killing 90% or more of the world's population is a positive, even if the survivors learn to knit.