It deepens the conflict between the Montagues and Capulets. Mercurio's death further enrages Romeo, leading to his impulsive decision to kill Tybalt, which sets in motion the tragic events that follow.
It highlights the consequences of violence. Mercurio's death shows how quickly violent actions can escalate and have devastating consequences, underscoring the play's themes of violence and tragedy.
It reveals Romeo's impulsivity and hotheadedness. Romeo's instant reaction to Mercutio's death shows his tendency to act impulsively and without thinking through the consequences, a character flaw that contributes to his downfall.
It contributes to the character development of Romeo and Juliet. Mercutio's death forces them to confront the reality of the feud between their families, deepens their understanding of the consequences of their actions, and accelerates their tragic journey.
It serves as a turning point in the play. Mercurio's death marks the transition from the light-hearted, playful atmosphere of the early scenes to the darker, tragic tone that dominates the rest of the play.
Overall, while Mercurio's death is indeed a tragic event in the play, it serves multiple dramatic functions that contribute to the conflict, character development, and overall plot progression of Romeo and Juliet, reinforcing the play's themes of violence, love, and fate.