Why does dally regret in regards to jonny?

Dally regrets not being able to protect Johnny and provide him with the guidance he needed. He realizes that Johnny, who idolized him, was deeply affected by the harsh realities of their environment and lacked the support to escape it. Dally's own struggles and hardened exterior prevented him from showing Johnny the love and care that could have made a difference in his life. This sense of regret intensifies after Johnny's tragic death, leaving Dally feeling helpless and remorseful for not being a better role model.