T
rying to stop the end of the world is a trope that annoys the hell out of me. It's always lazy when it comes up, but I particularly hate it in TTRPGs like Dungeons and Dragons. We as regular people have absolutely no experience with anything remotely like "trying to save the world"; so why is it landed upon as the goal of so many RPG campaigns?
To me, it seems obvious that it's an attempt to overcome the problem of motivation. The hard part of rpgs is figuring out how to get multiple players and characters engaged in the story. There are ways of doing this well, of course, and my favorite RPGs give you tools to make this easier, but lack of direction due to lack of motivation in the characters is a perennial problem, and it takes a skilful dungeon master to overcome it.
However; there's one thing everyone wants, and that's for the world to keep existing. Players' interest lagging? Just threaten the whole world (and, importantly, make it possible for them to do something about it), and bam, everyone's suddenly engaged. It's a cheap trick, but people don't notice the problem that generates it, and then it occurs so much that everyone just assumes it's the way things are supposed to work.
As a side note, I think this is why "nihilistic" characters show up so much in RPGs; characters who "just don't care" about anything. Subconsciously, people resent having their strings pulled in such an obvious way as "you have to save the world". So, to create any friction at all, they have to have characters that "don't care" about the world itself, at least for a little bit, until they are convinced to care. It's actually one of the only ways to engage in a multi-dimensional way with the world being threatened. But alas, it too is a cheap trick.