> ...given how useless it is I don't really understand why it even exists...

Ouch! 🙃

Lots of websites don't pay much attention to their print styles but this plugin uses those print styles to render the PDF - what you see in the PDF is most likely the same as what you would see if you were to print page. Some websites, on the other hand, do a good job - articles on Wikipedia and MDN docs, for example, look quite nice when saved as PDFs.

Some solutions:
- If you are having trouble with a web pages on particular websites, let the organization behind that website know they should support print styles.
- If preserving the look of the website is the highest priority, consider using screenshots - it's possible to capture the full page this way: https://support.mozilla.org/en-US/kb/take-screenshots-firefox (although the screenshot would not have links and selectable text)