Why Hamlet regret to Laertes in Act 5 Hemlet?

In William Shakespeare's play "Hamlet," Hamlet does not express any regret to Laertes in Act 5. Instead, it is Laertes who expresses his regret for the actions that led to Hamlet's death. Here's the relevant exchange from Act 5, Scene 2:

Laertes: I am justly killed with mine own treachery.

Hamlet: How does this satisfy you?

Laertes: To conclude, this:

Thou hast been as one, in suffering all,

That suffers nothing; a man that fortune's buffets

And screws have blanched or made insensible;

But, now, thou seem'st, with a most violent hand,

Self and our thoughts be crossed. Now, to do reason

And state to both, therefore, this peace of paper

The king himself hath sealed, and left thee here

For caution that he is so fortified.

In this passage, Laertes acknowledges his own treachery in poisoning the rapier and admits that he has been justly killed. He then expresses his sympathy for Hamlet's suffering and acknowledges that Hamlet appeared to have endured misfortune without showing any emotion. However, Laertes acknowledges that Hamlet's state of mind has changed and that he now appears to be reacting intensely to their crossed thoughts. Laertes goes on to present a sealed paper from the king, indicating that the king has fortified himself and left it for Hamlet as a warning.

Therefore, while Laertes expresses regret and sympathy for Hamlet, it is not an expression of regret by Hamlet himself. Hamlet's response to Laertes in this scene is marked by a sense of resignation and acceptance of his own fate.