Consider extracting structure/tags where possible in PDFs with the PDFMarkedContentExtractor

Some PDFs contain tags that may be useful in understanding the structure of the elements within a PDF, e.g. table markup, paragraph breaks, headers, etc.  

The quality of the tags depends entirely on the software and human generating the PDF.  There are no guarantees.  Nevertheless, it might be useful in some cases for users to be able to extract content with structure tags.

Some references:

https://acrobatusers.com/tutorials/what-are-pdf-tags-and-why-should-i-care/

https://www.adobe.com/accessibility/products/acrobat/pdf-repair-add-tags.html

https://www.pdfa.org/resource/tagged-pdf-best-practice-guide-syntax/