Question Why are Default Playables not available as a package or importable sample on the Timeline Package?

Same as title, why are Default Playables not available as a package or importable sample on the Timeline Package in Package Manager?

https://assetstore.unity.com/packages/essentials/default-playables-95266

 

Because otherwise you would not spend three days looking for documentation and tutorials, only to find some link in the description of a YouTube video from a 2017 conference

Default Playables does some interpretation of how to use Timeline, so I can see why it's not part of the package content.
However, I agree it should be an importable sample, as it's a very good showcase of how to make custom tracks and clips (the Playables wizard + the example Playables).