No one said it was as black magic. In the context of OCR and parsing PDFs to convert them to structured data and/or text, rendering is a completely different task from text extraction.
You're wrong. There is nothing inherent in "rendering" that means "raster or pixels". You can render PDFs or any format into any format you want, including XML for example.
In fact, in majority of PDFs, a large part of rendering has to do with composing text.
In fact, in majority of PDFs, a large part of rendering has to do with composing text.