In the context of the system where the currency was used, financial investments were not safe. It was the Great Depression, the inflationary nature of currency

In the context of the system where the currency was used, financial investments were not safe. It was the Great Depression, the inflationary nature of currency at the time made the only long term non superficial things structures, land, and goods. In the end, the things people do and build are what money is for. It’s a medium of exchange and a store of value. If it fails at these things, the making grain to feed people or housing them still has intrinsic value. You just need a working medium of exchange to avoid having to use barter for everything. If people trusted the town’s scrip more than the national currency, then they would use that. Investment in such a system would be in real objects and the means to produce them. Assuming people still cooperate and will accept your weird scheduled devaluation currency, then industrial society could continue to function and may even thrive, given people are incentivized to spend money which is the definition of economic activity. Also, other financial instruments might not be affected. Shares of stock, for example, would be worth what people would pay for them. It’s just big piles of literal dollars that you should get rid of expeditiously.