Okay but imagine is Snape survived the attack of Nagini. Like imagine how his relationship with people would have changed. Harry would forgive him after seeing his memory and I think so would Ron and Hermione. Because as we know Snape didn’t die from Abada Kadarva he died from Voldemort’s snake Nagini killing him, attacking his neck and thus Snape bleeding out, it is obviously unlikely that he could have ever survived but just imagine if he had. Imagine the connection he would then have with Harry. Harry would be able to see how much he loved Lily and how all Snape’s wrong doings were for the right reasons, like killing Dumbledore he would forgive him for killing him because he had to because Snape was told to. He would see the emotion and the heart that Snape actually had but nobody saw. And Harry would finally understand why he was so rude to him because he saw the woman he loved every time he looked into his eyes. He saw James, the boy who bullied him in school. And he couldn’t bare it because it hurt him. But imagine how Harry would reside and understand and finally Snape would be happy because he had a part of Lily back and that would be with his connection with Harry.
If Snape had survived so much greatness could have been made. His death is one of the saddest and most tragic.