I would really like to have TubeSync on my Cloudron instance. It is more than just a regular YT downloader, as it allows you to subscribe to channels and playlists. Every new video on your desired channel will automatically get downloaded, after it got released on this channel. But the best part - to me - is the playlist sync. You can create as many playlists as you want and add them to TubeSync, which will then download all videos to specific folders. This way you can download videos using EVERY device with YouTube access. All you have to do is to add a video to one of the playlists you sync with TubeSync and your server will download those videos for you.
I created some playlists like "interesting", "work", "tech", etc and whenever I stumble upon a video I would like to preserve I simply add it to the right list and TubeSync is doing the magic for me. No need to deal with URLs (besides the one time you have to set up a source in TubeSync).
As a bonus, it can also deal with meta, you can choose how files will be named, it can also download mp3-versions of videos (so you can create music playlists out of videos) and just in case you are using Plex, it can also update Plex and add new downloaded videos to it.
Source: https://github.com/meeb/tubesync
(Not a native english speaker - so sorry for any confusions)