@batzy seconding this, and I'll add an anecdote. When I was in college at the end of the 90's and the early 2000's, the way we got our textbooks in an accessible format, (not braille, just text we could read on a computer using a screen reader), was to buy two copies of a book, take apart its binding, feed the pages into a scanner, and then, once done, destroy/get rid of the destroyed books. Scanning in any other way meant a ton of time spent manually correcting the text, which added significant delays onto an already time-consuming process. That part of digital scanning of books hasn't really changed.