PDF is one of those weird “not for editing” formats, like STL. Hence why it’s often in an Export As dialog rather than a Save As.
It used to be even hackier. You’d have to get some separate PDF authoring software which would present to applications like a printer driver, so to create a PDF version of your document you’d start with the Print command, not Save or Export, then instead of your printer you’d select your PDF authoring software, then when you clicked Print it would create a file on your hard drive instead of hosing data down a parallel or USB cable to one of Satan’s Own Favorite Contraptions.
PDF is one of those weird “not for editing” formats, like STL. Hence why it’s often in an Export As dialog rather than a Save As.
It used to be even hackier. You’d have to get some separate PDF authoring software which would present to applications like a printer driver, so to create a PDF version of your document you’d start with the Print command, not Save or Export, then instead of your printer you’d select your PDF authoring software, then when you clicked Print it would create a file on your hard drive instead of hosing data down a parallel or USB cable to one of Satan’s Own Favorite Contraptions.