You generally do not control the process that generates the PDF or other unstructured data. Consider invoicing, you may have hundreds of distinct sources, but

You generally do not control the process that generates the PDF or other unstructured data. Consider invoicing, you may have hundreds of distinct sources, but none of them individually would warrant automation. It is a problem of standardization. Any standard complex enough to cover all business cases would be too expensive to implement, or you could not get all stakeholders to adopt it, and so on. Accountants would not want to make themselves redundant, obviously.