In the book When Money Dies, it was used to exchange for whatever the new currency was. How that will happen in a digital currency world I have no idea. The only way it helps is at the black market level.
Last month I was reading some update from the WEF that discussed the black market and that they know it will exist, a black market always exist, it did in Weimar. It was how people obtained the new currencies during the transition, it was how they exchanged into deutschemark, dollars, etc. to buy what they needed. Seriously, go read the book it might help you lay out your plan to survive this mess heading our way.
Check your library or order used from here: https://amzn.to/3lbHQyW