Fonts might or might not be embedded.

Paragraphs might be split into chunks, words, characters or simply outlines.

There’s no typesetting config. Nothing about margins, spacing, hyphenation, etc.

But then again, sometimes there is. The point is that it’s an output format.

Even Word, LibreOffice, InkScape, etc do to a certain extent.

I’ll work to a certain extent. Not sure how line breaks would work, but PDF is an extensible format, so these days they might include enough info to edit that