PDFs are an accessibility nightmare and most production pipelines are terrible at preserving the semantic structure of the document or, in many cases, even preserving the text. A PDF is in many cases as series of page images which aren't usable for anything other than human viewing or printing. "Export as PDF" generally produces much better results than print to PDF though not from every application. Many days I wish there was an alternative solution based on SVG. While not perfect it certainly would avoid many of the problems of PDF while having all of the important capabilities.