“This is inaccurate.”
Unfortunately, the vast majority of computer users are not computer-literate enough to know this. I have used Adobe Acrobat reader on occasion, but even I didn’t know about this function & having used computers & various programs at work extensively, I’m pretty well versed in such stuff.
If the posted files are scanned images of the pages, rather than PDF-printer generated text in PDF format, the search feature in Acrobat Reader and even Acrobat Pro is useless without extensive OCR (Optical Character Recognition) processing of the file - which would take hours, if not days, depending on the quality of the scans.