People enjoy a good story, but how often are we able to enjoy a good epic? "Game of Thrones" has a very small chance of actually having a satisfying pay off thanks to the writers at HBO and the life expectancy of George R.R. Martin, "Percy Jackson" is an epic for the children, "Harry Potter" has overstayed it's welcome, so why does it seem like it's all going away? Why do people seem to only enjoy typical Superhero films, the occasional horror flick, and tween-ish movies?
Funny enough, they're all their own style of legendarium.
They each tell a story of their own "epic" proportions. However, that's not quite the point I'm trying to make. People cling to epic stories of people overcoming adversity of unbelievable proportions using uncanny means. "The Lord of the Rings" took a little mythical creature and had him go up amongst the likes of goblins, dwarves, elves, men, and other dark creatures. No one could have imagined a hobbit, who lived in a hole in the ground, to walk a little ole ring to an erupting volcano! We need more of these stories!
Forget that Ross is trying to get with Rachel or that Kelly is obsessed with Ryan. People today need a story that they can get lost in and forget about the struggle of their lives.
The only piece of legendarium that truly exists nowadays is the Marvel Cinematic Universe. An entire world filled with characters who are extraordinary with amazing powers (or tech suits). 100 years ago, "Lord of the Rings" was dominating the literary world and would later go on to rule the cinematic world. However, in the times of the Ancient Greeks, there were tons of stories! The legend of Heracles, Perseus, then the tales of the Olympian gods, etc. As time went on, these stories began to fade. Different legends would begin to pop out throughout time, but at a slower pace and there weren't many at the same time.
J.R.R. Tolkien is probably the best example of this. He has a complete legendarium filled with so many characters that he could fill over 1000 pages of stories...and he did! His stories are even written as if he was a writer from these times because he was a scholar in those areas. It's part of his charm!
We're about due for a new series of legendarium. Where it'll come from, I do not know but chances are they're being written right now. I would say Martin is the one that is the best example for today...but he hasn't finished the stories yet, and probably won't. Tolkien is the superior author of legendarium and maybe he won't be usurped. He certainly won't in this writers eyes.