They will look back on Western fiction in the late 20th century and be embarrassed/amused at the utterly absurd and ridiculous "near death but look back from the brink just in time" tropes that were so common and so utterly beyond realistic. I think this will be remembered as our cultures inability to deal with death, and our fervent denial of it. How many times did the fucking stupid protagonist come back from the dead in the nick of time, or about 10 stupid things that would actually kill the characters happen but they just survive by a hairs breath. Yeah. If this is how you generate tension in your fiction, you're an idiot. Game of Thrones was so popular because Martin deliberately decided to deliberately break this rule. He has stated that in his fiction, you are supposed to feel like ANY character could get killed and noone is going to be spared because of their status as protagonist or relationship to him.
Some shitty writers have tried to do something LIKE Martin but not quite - dramatically killing off seemingly unkillable characters to shock us. Lost did this when it killed Libby and the cop woman, and it stank. A uk tv series called Skins did it the worst out of everyone ever, they killed off one of the main characters in order for his friend to kill the murderer. It was the most transparent, shitty 'twist' I've ever seen. Basically the show was a teen drama about hedonism, and after a few seasons they decided to introduce a murderous doctor which was just NOT permissible in the fiction world of the show. Kind of like an old timey cowboy showing up in a futuristic space story.
Anyway - saving the world - I don't think we really need to spell it out - its America and Americas denial of the existence of the rest of the world (it has to not really exist properly, or in a fallen state, since America has the right to murder it in order to liberate it). Noone really cares about this crap anymore because noone believes America is going to do anything to save them, apart from some aid work maybe. It's just as likely to destroy and plunder it.
That's why these narratives to have started to recede in the past few years and been replaced with apocalypticism - or rather - an inability to depict ANY end to the world, which is what people REALLY fear but can't consciously face. After Iraq the fucking end of the world american fiction industry went into overdrive.
Saving the world/destroying the world - how boring can you get? Primitive omnipotence fantasies should be something fiction aims to DISPEL and HUMILIATE not bolster.
I'm not saying that narratives about the end or salvation of the world are themselves unacceptable, it's just that this is the most played out trope currently in existence. If you want to save or end the world, making the world itself revolve around the drama or journey of a few characters, so that it lives or dies depending on what needs to happen to them, is IMO not particularly interesting.