People like to be intensely involved in a task. They like to get an adrenaline rush. They like to find they are safe afterwards.
There are many different ways to get adrenaline rushes. Violence does it. Horror movies are good at it. Video games can make it happen. But so can love stories. Any kind of tension can make us feel it vicariously.
Tension and release. Tension and release. I would say it could be cathartic. But also getting your adrenaline going a lot can turn you into an adrenaline junkie where you need greater and greater thrills in order to achieve the same excitement level. Better to have sufficient time in between so that the previous level of excitement does it again, I think.
Getting out aggression, though, is another story. I’ve heard that releasing aggression may not be the best approach. It is better to learn other coping mechanisms: ways of letting go and relaxing. Again, expressing aggression can make you want more rather than releasing it. It can make you get high on the adrenaline and used to using aggression to get high. You can become ill equipped to let go of your anger, since you like holding onto it in order to get your adrenaline high.
So I would be careful about violence. I’d be careful about allowing a child to do something compulsively or obsessively. I think moderation is necessary. In moderation, it is manageable. But if one learns to do something over and over and over without end, one is setting oneself up to learn obsessive and addictive patterns of behavior.