AloofChocolate some ROM vendors decided to keep the toggles as they were. Unfortunately, the GOS team already stated that they don't want to stray away from AOSP too much and likely won't change the toggles.
For turning off mobile data I think it's easy enough to just use the tile. Getting to mobile data settings is a little more annoying, but a long press on the tile already brings you halfway there. I got used to it after a while.