Prehistoric basically means coming from a previous time.
It may denote inferiority(or may not, it hasn't to be inferior).

But there's a problem with the concept "that culture is inferior, thus they're more prehistoric"... And it's that many cultures with unequal charachteristics are usually civilizations or at least in the Iron Age/Late Neolithic.

Those CULTURES AREN'T PREHISTORIC BECAUSE they're LESS DEVELOPED, they're just LESS developed.

One civilization is better than the other. And the worse is also a civilization, it isn't prehistoric.
And that also means that the DIFFERENT PREHISTORIES over which LATER CIVILIZATIONS ARE BUILT AREN'T THE SAME.

A tropical hunter gatherer of small fishes doesn't build the same shacks that a EHG/WHG built. It neither has the same brain size.