This presupposes that consumers have infinite capacity to ingest the minute details of every single product they come into contact with.

Yes, the plastic bag has users. Do you really expect every single shopper to investigate how the bag at <grocery co> was made and if the plastic is recycled? What if they also have to do the same for every single thing they interact with every single day?

It's much easier to ask the people that work with the minutia of plastic bags every day, namely the people who make them, to maybe fix this problem.