Good thing too, because the current setup is rather confusing. I often want to go to System Settings and end up going to Budgie Settings instead, because it’s not clearly labelled in Raven (not to mention that the settings shortcut at the bottom used to lead to GNOME Settings).
If my memory serves me right, Cinnamon did much the same thing. They originally had a supplemental control center for the Cinnamon-specific settings, and then they replaced GNOME’s control center entirely. Good call on their part.
Don’t have it open in front of me, but I believe that the settings under the “Notifications” section also do nothing under Budgie.