PDF to Text, a challenging problem

When accommodating the general case, solving PDF-to-text is approximately equivalent to solving JPEG-to-text.

The only PDF parsing scenario I would consider putting my name on is scraping AcroForm field values from standardized documents.

This is approximately the approach we're taking also at https://doctly.ai, add to that a "multiple experts" approach for analyzing the image (for our 'ultra' version), and we get really good results. And we're making it better constantly.

If you assume standardized documents, you can impose the use of Tagged PDF: https://pdfa.org/resource/tagged-pdf-q-a/