When I tried doing mechanical turk jobs out of curiosity, one of the tasks was checking/amending OCR'd receipts. (image on the left, textbox on the right)

It was less than a cent per receipt, but doing each was much quicker than 30 seconds. This was in 2017, to give you some idea how good OCR was.

Even before then, I've been disappointed no major chain encodes the receipt data into a QR code or something at the bottom of the receipt to side-step this whole thing. The closest you get is some places doing digital receipts nowadays.