So I wrote a free application to download the video wallpapers found in macOS Sonoma.If you haven't seen it, Sonoma now offers the same videos that were used as screensavers on the Apple TV for use as wallpaper and screensavers. They are browsable from the terribly redesigned system preferences.

If you click one these, it'll download it. Apple does not make it clear where these land, but it is in:

/Library/Application Support/

However, I wanted this to work on non-Sonoma nd to be a bit easier to download so I wrote an app to make it easier, Sonoma Video Wallpaper Downloader and the github page.