[Announcement] Upcoming new requirements for YouTube downloads · Issue #14404 · yt-dlp/yt-dlp
github.com
Beginning very soon, you'll need to have the JavaScript runtime Deno installed to keep YouTube downloads working as normal. Why? Up until now, yt-dlp has been able to use its built-in JavaScript "i...

So, starting now, Google started mandating full JS for YT, effectively breaking all third-party clients and locking the site to their official client.

This reeks of DRM.