Not for scanning barcodes; I've seen them in action, they're noticeably slower and the image processing seems more involved than whatever magic is in barcode scanners.
The barcode scanning in the Libib app (an app to keep track of books) seems quite fast, it is quite addictive to just zap the barcodes and see the book data added to the catalog.
It seems comparable to the laser based scanners used at library checkouts for example.
They sure beat camera based ones yes (although they technically also use a camera but it's really optimised for the purpose)
Most of the couriers that come to my door also use these or similar, not standard smartphones.