Today I just witnessed Cast Connect on Youtube app (
https://9to5google.com/2020/08/06/cast-connect-android-tv-apps/
)
I connected to my Android TV from Youtube App on Mobile and played a video, to my surprise I was able to control it from my Android TV remote.
This is new after google announced this recently. This needs a change from app to be able to do that. On android tv it would just start a web cast session earlier
How YouTube casting from another device to my Nvidia Shield TV works:
Casting to Shield TV's built-in Chromecast. Chromecast's built-in player activates no matter what app is running on Shield TV. Controllable with the Shield TV's remote but because the player has its own UI much YouTube functionality is unavailable. After playback, previous app resumes.
Casting to paired device ( https://youtube.com/pair ). YouTube app starts if not already running, and plays the cast video with native YouTube UI. Playback is controllable with either source or destination device. After playback, suggested videos appears as with any other YouTube clip.
(Also, in my experience, option 1 only actually works 10% of the time; I had to switch to option 2 to actually get casting to work. I do not know if this changed with the recent Shield Experience 8.2.)
It sounds like Cast Connect is Google expanding option 2 to other apps. YouTube pairing functionality is supposed to be going away so this is good news for those of us who prefer it to option 1 (again, when it works).
I hate this, I'm keeping my Android TV with an old youtube version. Sometimes I need to cast a video with my 2nd account but it will connect to the youtube tv app with my 1st account logged, and then those videos would be in 1st account history.
If it had an account switch at least.
It has always done that for me.