There may be many reasons why cats like to fight. One possibility is that cats are predators, so they have an innate instinct to hunt and protect themselves. Fighting may be one of the ways cats practice their hunting skills and protect themselves. Additionally, cats may fight over territory or food, or become hostile because they feel threatened.
If your cat fights a lot, you can try observing their behavior to see if there is any specific reason why they are becoming hostility. If this is the case, you can try to avoid these factors or provide them with more other activities to solve the problem. If your cat fights frequently, you can also talk to your veterinarian to see if there are any medical issues that may be causing their aggressive behavior.