It's because YouTube is now requiring a full JavaScript runtime in order to download and play videos. There are open issues regarding this in the relevant GitHub projects, but the fix has not yet been released.

https://github.com/yt-dlp/yt-dlp/issues/14404

https://github.com/ytdl-org/youtube-dl/issues/33186

See also previous HN discussion: https://news.ycombinator.com/item?id=45358980