There are few, but real use cases for storing and exchanging Nostr events in paper, inside QR codes directly. An extreme version of P2P privacy.

A legally-binding contract signature for instance, doesn't need to be online or even be stored digitally. The entire signed event can be printed inside a QR code, exchanged offline and erased from electronic existence to only come back online when absolutely needed.

Once you give people private keys and a common data model, the ways to exchange those payloads are endless.