It's a tool to make a bank-like thing. Whether that's for a small high-trust community (maybe your Urbit sponsor runs a mint), or a cloud computing resource allocator, or a full-on "bank with insurance and legal protection". It's just a primitive for [give me x and I'll make sure you get y], and it's various implementations will be better or worse for different use cases.

For nostr micro payments it seems perfect. I'll still of course have legit onchain BTC for actual high value savings.