This app was mentioned in 5 comments, with an average of 2.00 upvotes
It’s possible to stream Bluetooth audio to Google Home but not sure if the respective apps require the phone screen to be active.
Alternatively, you can try TubeCast app.
just in case some one needs this - TubeCast for Android link, it casts only audio, and can loop, suitable for listening music without video
adding TuboCast - a new one that cast youtube to chromecast audio without youtube red :)
This is kinda possible with certain apps. Here's on that works pretty well on Android https://play.google.com/store/apps/details?id=com.sibimobilelab.castwebaudio&hl=en
Here's the shortcut to the playstore https://play.google.com/store/apps/details?id=com.sibimobilelab.castwebaudio