I work for a global consumer goods company - we print probably billions of (1d) bar codes on packs per year.

1d bar codes will go extinct, but only after every scanning system at every retailer has changed to recognize 2d bar codes/qr codes. This will likely take decades.

In the meantime, there will be a world where 2d bar codes and 1d bar codes will coexist on packs. With the additional confusion that many packs already have qr codes, either for consumer information or for internal tracking at the plant (batches for quality control), so we will probably have a little zoo of qr codes for a while, until they all finally can be merged.

How do manufacturers print QR codes on packaging that potentially could change daily, like in the case for expiration dates? 1D barcodes don't ever change so they can be easily printed in mass on the packaging.