A very interesting post, @lukestokes. This is something I've been thinking about for a while (just like most commenters here). Let me quickly share my thoughts.
The financial collapse you are describing will have many, many unforeseen effects. One thing that will certainly be affected are the large-scale systems we are dependent on, most notably electricity and internet connectivity. And these two things are key to running cryptocurrencies.
The other area that is most likely going to be affected is the individual and collective human psyche. While we can sorta guess how the electric grid will be affected (blackouts), it's incredibly hard guessing how humans' behavior will react. Desperation? Bursts of pointless violence? Hedonistic abandon? Depression? Suicidal tendencies? Maybe a mix of all this? In any case, under those conditions I think it would be even harder than with today's apathy and complacency to get people to adopt a new way of exchanging goods and services.
For those who keep their calm and reason, it may not even be necessary to formalize the transactions online, especially on the local level. As experience shows us, in times of crises people can come up with alternative means of exchange in mere minutes, such as using cigarettes for exchange. Coupled with that you add barter, or even gift economy, so you can at least get off the ground and maybe put some food on the table for that day. Later on, once people have gotten over the innitial shock, THAT is the time to introduce alternatives to what we used to know as banking, finance, and coining currency. Provided, the necessary infrastructure is in place.
My greatest concern, however, is the second point. After all, before people started bartering with cigarettes, usually they had been through months (years?) of food rationing, bomb raids, the daily loss of life, and a gradual loss of material and social structures around them. I don't know if it will be the same if suddenly our only means of measuring wealth and exchanging goods becomes null and void. Though one thing that may be able to prepare us for it, is at least discussing this possibility before it happens. Which is why I am happy to read this article of yours and comment on it.
Thank you for your comments.
I can think of a friend whose wife lived through multiple currency collapses (local money literally going to zero) and they always seen to adapt and survive. Old money is replaced with new money. I think that can happen again but instead of the loop, they could decide to use self-soverign money uncontrolled by the violence of the state.
Yes, it's possible internet and electricity grids may shut down, but the people running those installations want to feed their kids also, so I could imagine a scenario where they get onboard with getting paid in cryptocurrency also. That said, I do hope we move towards a more decentralized approach to electricity and connectivity.
If people are scared and freaked out, maybe cryptocurrency would be too much for them, that's a good point. I still think it would be easier than, for example, cigarettes though, as long as at least a portion of their network (15%?) were actively using it, accepting it, promoting it as a valid option, etc.