We have human records painted on cave walls, carved on rocks, clay tablets, various kinds and types of paper, going back many 10's of thousands of years. Writings from 2 to 3 thousands of years ago, compared to what we see today, but are told were written thousands of years ago, that don't agree with the original records. It is fairly easy to figure out sumtom ain't right here. Reliance on magnetic polarization, not so much, without access to the proper computers, hardware and software decades after they have been replaced.
Yet we have already lost valuable information because there are no computers left in existence that can read the data bases. Computers built, used and discarded well within our lifetimes. (Or at least mine)
Upgrade the computers, and/or lose the electricity and poof, our ancestors can never recover that information decades later. There can be said good things about file cabinets for long term storage for critical information.
Too heavy a reliance on computers will bring about the downfall of civilization, when things go pear shaped, as all civilizations have encountered so far.