With books read aloud videos you can use youtube-dl (which can download videos from most websites) and then you have an audio book for offline listening. You can even rip the audio out so it's an audio file instead of a video. Not expecting users to do that to submit here, just and FYI for those who may not have thought of doing that for themselves.

With books read aloud videos you could use youtube-dl (which can download videos from most websites) and then you have a free audio book for offline listening. You could even go one step further and rip the audio out so it's an audio file instead of a video.