Use document scanners instead of barcode equipment when the complete page—not a compact identifier—is the authoritative artifact. Signatures, handwriting, stamps, annotations, graphics, layout, page sequence, and visible condition may all carry meaning that a decoded barcode cannot preserve.
The decision boundary is what must survive capture and what happens next. Document scanning creates image packages for OCR, classification, indexing, review, repository storage, and retention. Barcode scanning recovers structured payloads for fast lookup and operational transactions. A barcode may help index a document package, but it cannot substitute for capturing the pages that the index describes.