The problem is that there are other AI players in the game who want to dominate the map and destroy you. Eventually, you build your way up to future tech where you have walking robots and hyper-fast bomber planes. The aim of Empire Earth 3 is to start with your cave dwellers and have them gather resources and construct buildings until they have enough resources to advance to the next stage in human technology.
Softonic review Build your empire and progress your technology through history