Besides the irony of digital files, there's the fact that these just seem to be scans of old books. That sounds nice in theory (wasn't technology in olden times

Besides the irony of digital files, there's the fact that these just seem to be scans of old books. That sounds nice in theory (wasn't technology in olden times simpler and therefore easier to get going after the collapse of civilization?) but the problem is that the materials described might not be that easy to find in the modern world (even without an apocalypse). I once tried to build some devices described in a 1920s electronics book but was stymied by the complete unavailability of many components.