Here are a few counter points. Not all PDF are the same. If it does not embed all the fonts required to render it, it is not future proof and of archival quality.
PDFs are also excruciatingly hard for screen readers, thus lacks accessiblity. Copy pasting text often misses whitespaces, making life hell for normal folks.
@abri you can create PDFs from (for example) markdown, using a tool like pandoc, and apply a different style sheet to regenerate it with a different look. This way you can run a script with new stylesheet to regenerate all PDFs making up your site in one go, rather than manually editing each one.
Server run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!