It's not in the general settings - instead it's in the setting menu in the video player itself, where you'd select the quality and playback speed, etc.

its not there for me. I dont see it in any settings anywhere.

Is Dark Mode in either your OS or Youtube turned on? It's not an option unless you're in DM.

I stopped doing per-site dark mode and just use the darkreader extension, which is why this option was never there. I call it a win to not deal with per site settings.

oh, I never use dark mode so I guess that is why I don't see it.

I don't see it either, maybe it's on an A/B rollout for desktop.

If you use uBlock, add the following to the filters:

  youtube.com###cinematics.ytd-watch-flexy