Let me show you the historical origins of protoss (pure spirit, pure energy), Zerg (pure body, pure energy) and Terran (earth human). In the same galaxy, for food, the Zerg wiped out all the living things on Copolus, the planet where humans live, and the Zerg almost wiped out the protoss. In the end, the three families were deadlocked, and people, insects and gods broke out.
From the game level, we can find that in order to survive in the war, people, insects and gods all need rich and high-quality mineral raw materials. Without such resources, no war machine can be started. As we all know, the raw material of this mineral is mineral (crystal ore), and the other raw material is vespene gas (high energy gas). High-energy gas is mined in the form of gas, which is the most abundant and efficient fuel in the known universe, so this is the fundamental problem of the war between the three races.
From the point of view of survival, there are all kinds of conflicts between different races, mainly because of their different lifestyles and concepts, which leads to great differences, and finally makes it impossible for people, insects and gods to survive. Only in StarCraft II, their three-clan alliance killed Armon, which was also a happy ending.