Depends if you’re talking camera negative, interpositive, internegative, or release prints. Each one is a step down generationally and each one will have less detail to be captured than the last.
So in theory, camera negative is the way to go, as it has the most detail. But then you have no color timing information - you’ll have to go the interpositive or internegative from which the release prints were struck for that, and boom, you’ve lost two-three generations of detail. Or you could scan the o-neg and match the color grading to a reference print (interpositive or release print), but that still opens the door to revisionist color timing.