What do you think about the subplot revolving around the characters of Feste, Maria, Sir Toby, and Sir Andrew?

Twelfth Night is a comedy, but there are definitely some very dark moments in is, as is true for any Shakespearean comedy.

Bearing this in mind, what do you think about the subplot revolving around the characters of Feste, Maria, Sir Toby, and Sir Andrew?

Is this part of the play funny or not. Explain your answer, especially when it comes to the end of the play. Is this subplot wrapped up in the ending? How does it affect the ending of the play?