Why would you want to convert from EPUB to PDF? There are a few very valid reasons for this. PDF comes with many advantages that EPUB and other ebook files don't have.
While you need an ebook reader to read EPUB files, in most cases, you can open PDF files almost everywhere. On your computer, on your phone, even in your browser – PDF documents are supported by many programs and apps.
Furthermore, PDF files are optimized for printing. Thus, they are perfect for creating physical copies of your EPUB files.