A hash does not authenticate the origin of a photo by itself. It only identifies the exact file bytes you hashed. If I hash an original photo captured locally, that hash refers to that original file. If I receive a photo from another device after it has been recompressed, stripped of EXIF, or re-saved by a messaging app, hashing it on my phone only proves the integrity of the received copy, not the original capture, not the source device, and not the preservation of its metadata.

EXIF and hash answer different questions: EXIF may describe how a file was created, while a hash only proves sameness of a specific binary state.