I built my own personal version where it runs in the background and automatically downloads stuff I like (I highly curate my likes) or send to select playlists. Too often I go through my favorites and see deleted videos so I just cooked up something one weekend. I have an entire hard drive dedicated as an offline archive where I can playback at anytime, search the library and it even alerts me if any video or audio I saved was deleted (I have quite some rare pulled videos). It will also grab the subtitles/transcript if available, description and top 100 comments (if a tutorial etc).
https://i.imgur.com/yxlRTI8.png