Like Hollywood, many GMs are under the impression that the bigger the Threat to Existence, the more compelling the story will be. In my opinion, that's not going great for Hollywood right now and it may not be working great for your campaign either.
What's Bigger?
One problem with Epic storylines is that if you revisit a storyline based on saving All of Existence, your next story has to be even bigger (Dragonball Z)! Because it has nothing else really going for it except spectacle, does it? Sooner or later, you or your players will either get fed up with increasingly outrageous ways to threaten the universe (Star Trek: Discovery) or you'll just reboot or abandon it.
Not every story needs to be about saving All of Existence. Heroes can get just as much or maybe more enjoyment from just saving a village from the Barbarian Raiders. But if the heroes are working to save a village, I bet the village will know about it.
All Alone in the Night
Your heroes fight the spectacular battle with the Forces of Naughtiness, and though it was tough, they prevail. But... I've noticed a trend in Epic Stories where the world isn't necessarily aware it is in any danger, only the heroes and the villains know what is truly going on. And while a heroic victory without seeking glory is very noble, this is a game of Fantasy. Your players might be looking for some positive reinforcement beyond treasure for what they've done. How about a parade, or at least a heartfelt "Good Job" and "Thank You". Your players likely aren't getting thanks in their real life.
However, all too often the heroes stand alone.
Take Luke Skywalker in Return of the Jedi. During the final battle over Endor, Skywalker has a serious battle of his own going on and the death of Palpatine and Vader may have helped turn the tide of the war. But I doubt anyone except Leia was told about what when down. There are parades for the Rebellion, but not for him. Very noble, the cause is more important than the person.
But! Your players might prefer a different ending, one where the people being saved know that the heroes are there doing what they can. It's all unfolding right in front of them. And when it is all over, the heroes get the recognition they've earned (see Army of Darkness).
All I am trying to say is that if the world is in constant danger of being obliterated every week, what does that say about the world? If the novelizations of Star Wars are to be believed, Republics are made out of tissue paper.
And the Mandalorian? He just wants The Child back. That's all his story needs.
