I would say that calling any of them futuristic is baseless. the worlds in VII and VIII contrast high technology with low tech, as has happened in every FF world since I. In Sky Fortress, you have computers analyzing Tiamat, and robot soldiers trying to stop you every step of the way.
Alot of the technology in VII isn't futuristic, their vehicles are all very crude. alot of shinra's machinery was supposed to have a World War II look to it. In VIII, you have futuristic civs like Esthar, but then you have modern ones like Galbadia, and older ones like Windhill.