In Shakespeare's “Romeo and Juliet” the person that is responsible for Juliet's untimely death, is Romeo for capturing her love and convincing her to love him back no matter what.
If Romeo didn't meet Juliet or did not admit his admiring love to her, none of this would've ever happened. Romeo should've thought about the consequences of becoming in love with his kingdoms moral enemy before he decided to chase after Juliet.
Also, Mercutio, Paris and Tybalt wouldn't have been killed. All of this mess would've never happened if Romeo just either got over his ex and moved on or got back together with her.
Theres plenty of fish in the sea and Romeo just had to pick the one single fish that he wasn't allowed