Saving Attachments with Filenames

If you right-click on a note or notebook you can export as MD - Markdown. This puts the notes as markdown files into a folder named after the notebook and all the resources get exported into a _resources folder with their filenames not the Joplin ID. The links to the resources in the Markdown files also get changed to a link to the named file.

Using File > Export all > MD - Markdown will do this for all your notes.