Why did the ancient Greeks decorate temples primarily on the outside, and the Byzantine craftsmen on the inside?

They decorated their theaters with equipment, because the ancient Greeks did not go inside the temple. They prayed and offered sacrifices in front of the temple itself. Thus, the temples were beautiful on the outside. The Byzantines were Christians, and therefore, in their temples it was customary to pray inside. Thus, the temples of the Byzantines were decorated from the inside. Nowadays, basically all churches and cathedrals are decorated from the inside, and not from the outside.