One of the key themes of Hamlet is the connection between the health of a nation and the state of its rulers. Claudius is rotten, and in this scene, we see that Denmark is starting to rot as well; there is civil unrest, mobs storming the castle, and echoes of revolt against the current king.
Here, the difference between Laertes and Hamlet becomes most obvious. Each has a dead father to avenge; but while Laertes acts openly and with moral law on his side, Hamlet has failed to act and has forefeited any position as the “good guy” by killing Polonius. Unlike Hamlet, who is consumed with thoughts of ethics and revenge, Laertes spends no time questioning what is right in the situation. He simply acts.