NewPipe is excellent. I was disappointed that it was not available for desktop until I discovered tartube which will download video files from almost any website easily
JDownloader, youtube-dl, yt-dlp and many others can also download YouTube videos (and hundreds of other sites). Yes, the last two are command line tools, but if you put them on your desktop you can just drag&drop any YouTube-link on them and it will download it for you
Stacher is a decent frontend for yt-dlp for the command-line averse.
I also recommend FreeTube, which sounds like a porn site but actually it's another open source desktop YouTube player: https://github.com/FreeTubeApp/FreeTube
Oh neat, looks like tartube is a GUI frontend for youtube-dl.
It defaults to youtube-dlp but can be toggled back and forth with youtube-dl.
What's the difference between the dlp and dl versions? I've only ever tried dl.
youtube-dl is unmaintained. yt-dlp is a maintained fork