When people open an item I sent them, they look at it and use it and throw the package away. On the off chance someone tries the QR code and are directed to NOSTR, their reaction as a normies will be "wtf is this" and leave. No one does the 2nd step to get an NPub. If they are normies is what I'm saying.
Some time ago there was a guy who supposedly worked on a place that issued a bunch of these code things and managed them and he wanted to make them on Nostr, I don't remember exactly.
The guy has vanished, but his spirit came back and now nostr:npub10000003zmk89narqpczy4ff6rnuht2wu05na7kpnh3mak7z2tqzsv8vwqk has wrote this nice proposal.
Except for the fact that real-world implementation will take a million years I like it very much (except for the 'nproduct' new bech32 code).
Discussion
Just like 99% of people throw the tags with the barcodes away when they bring a product home. And I don't think we're talking about the end consumer here, an nproduct ID could be used by the Supply Chain to track materials and the manufacturing, shipping and distribution process of a product or service. If we could get this worked out, it could be a huge part of a global VAT system.