I am pretty sure it is a separate app that you have to install?

https://9to5google.com/2025/11/05/pixel-theme-packs/

Also bad: On Volvos†, you are now prohibited from uninstalling the YouTube app.

I don't want to watch videos while I'm driving.

In the previous software, you could at least move it somewhere unobtrusive; but the latest version only displays icons alphabetically. No re-ordering anymore.

† Volvos have "Google Built-In," the bastard stepbrother of Android Auto, which also has an app in the car so you can have the worst of both worlds.