Someone else posting to HN used cheap flash cartridges for a "music player" like this. There is something to be said about having a ROM or ROM-like media that can store even a few megabytes of data rather than QR codes being relatively bandwidth limited and so often needing a URL to data or more URLs.

The article points out there is a useful lesson in accidentally destroying/losing a physical object in the way that floppies or VHS tapes were easy to accidentally destroy and taught young childhood lessons. QR codes are a bit harder to destroy, which can be a benefit, but also loses this tiny lesson.