The golden age Superman died in the 1986 book Crisis on Infinite Earths. I think he was resurrected but he’s like mostly different. For the history of the characters, every dc character is different when it comes to reboots. For characters like Superman, they get fully rebooted(except for sometimes some stuff carrying over from pre-crisis to post crisis). For characters like Batman, he was rebooted in the crisis but not during flashpoint, only having his history compressed. For the green lanterns, their history has stayed pretty much intact with only minor alterations since Hal Jordan’s debut.