How practical is it really? Having to print and track individually serialized barcodes for every product you sell, sounds like it can be anything from a nearly 0 cost step to a complete logistical nightmare depending on the manufacturing process.
The whole thing sounds like it's a really obvious and simple solution at a glance, but as you dig into it it seems hard, especially for smaller players, and only shifts the counterfeiters' workload (now you need to figure out how to steal barcodes, not impossible depending on how much money you invest).
The difference is that Amazon is exceptional at tech and has the marketplace to implement and improve their solution over many years. Hopefully Amazon's solution becomes cheap and easy to use for even small brands (but realistically it only needs to be less expensive than the cost of counterfeits to be adopted).
If Amazon's Transparency is REALLY GOOD, they could offer it as a service through AWS. There's an enormous demand for this sort of solution.
Example, my Dad published an e-book he sells through Amazon, and I'll be damned if there aren't other Amazon sellers offering my Dad's book for sale...its ridiculous.