yt-dlp which the article links allows for auto filenaming templates that support channel name (or ID though it consumes more filename length) and the service it was from (eg: Youtube, Vimeo, Reddit). If you add the option to save metadata to the video (with the required dependencies) it also saves the full URL to the file, depending on the service.

A more robust method is also saving the full metadata to a separate JSON (though if one likes to rename files then it has to be remembered to rename both the files).