Why aren't there any chip manufacturers in this apocalypse? Somehow, humanity's collective knowledge of how to make computers/adding machines is lost but someone manages to recover the entire 600GB Blockchain even tho there are no books/printed words? I think there are just as many (if not more) offline/faraday backups of Wikipedia than the Blockchain.

Let me present a more likely senario:

Disaster happens and the Blockchain stops adding blocks because every computer on earth has been permanently disabled.

Many people will have cold storage Bitcoin seeds memorized and/or recorded in ways that survive the disaster.

Without new blocks, the coins on these keys cannot be spent. You can't even give someone else your seed in a trade without trust because you also know the seed and could doublespent them once the Blockchain resumes.

Consensus only cares about the Blockchain with the heaviest proof of work. So anyone who decides to try and mine blocks by hand, and distribute the newly found block without internet is wasting their time because all the work they do could easily be undone by primitive adding machines and a network of telegram wires or radio stations.

Even if one community decided this was the best strategy for them, they would struggle to enforce the consensus rules without trust since it's no longer feasible for everyone to validate the transactions themselves without checking all the work themselves by hand. People under this limit, would just trust whoever is disseminating these new "blocks" to people.

It's like trusting the phone companies to make sure there are no typos in the quarterly phone books sent to every household pre-internet. Very centralized. People would have to submit their txns directly to the block factory and hope they get included.

Even if you did find an error in a block, what are you going to do about it? Try to convince everyone in town to discard the last block and force the block production factory to issue a recall and replace it with a valid one? It just wouldn't scale at all without becoming completely trust based.

It soon becomes obvious that Bitcoin was designed for networked computers and humans are really bad at computing/networking. Especially, when most people are just trying to survive and could care less about keeping their ledgers updated and verifying the transactions of their neighbors too!

Instead of doing math by hand or with a slide rule, then shipping tonnes of paper with hashes and hex encoded text to every community on the planet, we would all be better off working towards getting BTC back to running as close as possible to how it was before the disaster.

In the meantime, communities will just use ancient money technologies that run better on the available infrastructure.

At worst case, 2016 new blocks would need to be mined at the pre-disaster difficulty before the next adjustment. The difficulty can only go down 75% at once, so it could take a few adjustments before we're back to 10min block times. The time between those first few adjustments could be decades.

Assuming we have to rebuild global communication infrastructure, there could emerge multiple BTC forks or chain splits as new communities develop the technology to "resume" the Blockchain independently using what they believe is the current chain tip.

These forks could persist forever as national treasuries or lose value to alternative blockchains with greater proof of work as they are discovered and the world reunites.

There would also be a huge opportunity for shenanigans since compute isn't evenly distributed anymore. The earliest miners would be in very powerful positions to reorg the chain that could be very politically impactful since blocks could take years to mine in the beginning.