Tonight, I tested out Rapid PDF Count, a utility from Traction software, available for download here. A license costs $80. The software is designed to generate a count of the number of pages in a set of multiple PDF files. It will process all PDF files in a selected directory which has multiple subfolders.
Under setup . . . options, you can check off a box which will set the utility to also generate a word count for each of the PDF files.
The list Rapid PDF Count generates can be exported. It's a good way of finding which files in a directory have not be made text searchable. Note there's a field which indicates whether or not there are searchable words on every page of a PDF file.