Help articles say I need a Chromecast to link to YouTube, but is there a
way I can just cast from the Best Audio to the existing TV app the same
way that I do on my phone?
Exact same issue, and all I can find online are other people describing
the same thing and zero response from Google (big surprise there). I
even found one post where the community guide suggested contacting
YouTube Music support but the site was bro...
So no, there isn't a non-chromecast method to make the Nest communicate
with the YouTube app like other Google devices can. A walled garden is
what I wanted to avoid yet I fid myself in one anyway.