You would think, but in the lore Pokemon do just casually form fight clubs and have small wars. In addition, something about teaming up with humans allows them to unlock power boosts or just having access to a coach. Granted, the levels of intelligence and similarity to human psychology can vary from Mon to Mon. One example is that Basculin in the lore is basically just a violent trout, making it less of a moral concern to many in-universe gourmands. Meanwhile other Pokemon like Alakazam or Orangaru is effectively a human with magic powers.