Taylor Swift closed her Eras tour on top of the world. Now what?

The nearly two-year-long, $2 billion Eras tour shattered records, made history and quite literally triggered earthquakes -- so what could Taylor Swift, the planet's biggest star, possibly do next?

"Taylor Swift just needs to rest, frankly," said Andrew Mall, an ethnomusicologist at Northeastern University.

It's a wholly reasonable sentiment when you look at what the megastar, who turns 35 today (13 December), has accomplished, including releasing nine albums in five years alongside a concert feature film.

The career-spanning global odyssey of a tour she just staged was like nothing that came before it: 149 shows across the world that typically clocked in at more than three hours long each.

Eras tour tickets sold for sometimes exorbitant prices and drew in millions of fans, along with many more who didn't get in and were willing to simply sing along from the parking lot.

"I think she can't top it right away," Mall told AFP. "There's just no possible way she can turn around and launch something else that has as large an impact, cultural and economic."

For Kristin Lieb, an expert at Emerson College on pop, gender and branding, the question of what's next isn't even particularly fair.

"The minute you finish a marathon, or the minute you win the World Series, or the minute somebody gets tenure, you know, the first question is, what are you going to do next?" she told AFP.

"I'm starting to make sense of that as a real cultural sickness."

'Up to her'

But in an industry that's constantly seeking what's young, new or fresh, "what's next" is nevertheless always front of mind.

The Swifties are still waiting on more "Taylor's Version" albums: Since 2021 Swift has been making good on her vow to re-record her first six studio records in a bid to own the rights to them.

She's got two left, "Reputation" and "Taylor Swift."

Swift also has the Grammys in early February to look forward to, with six nominations including three in the most prestigious categories for her latest studio album, "The Tortured Poets Department," her fifth since 2019.

At this year's gala she used her award acceptance speeches to announce that new album -- another surprise up her sleeve would surely delight fans.

But looking past "what's next" is perhaps a larger question: how does an artist define success when they're already a cultural phenomenon, awash in riches and fame?

"The good news for her is, like, she's literally the biggest star in the world, and so that is entirely up to her at this point," said Lieb.

Live albums, a Vegas residency, further extending her incredibly recognizable brand into products? Anything is possible at the House of Swift.

Years ago it was announced she had penned an original screenplay and would be making her feature directorial debut with Searchlight Pictures -- so maybe she now has her sights set on the Oscars.

Swiftie loyalty

In any case, at this point Swift doesn't necessarily need to keep her fans constantly fed to keep them loyal.

She's fostered a community that is somewhat self-sustaining -- a contemporary, mostly online version of the fan engagement the Grateful Dead pioneered, which saw Deadheads commune in their reverence for the band.

Swifties might honor a request from their beloved to give her time and space, Lieb said -- "I do think that she's cultivated a relationship with them such that they could hear that and respect that."

The Eras tour, Mall pointed out, also bloomed from years of prolific music-making and audience-building -- so she might need time to develop more material before accomplishing another feat of that magnitude, if that's a goal of hers.

And in the mix of everyone else's expectations, Lieb said Swift might want to take a moment to consider what it is she herself wants: "What would be challenging and fulfilling for her?"

Swift does of course have a personal life, famously so: for more than a year she's been very publicly dating NFL star Travis Kelce, and might want simply enjoy herself and the fruits of her labor.

And in the grand scheme of it all, a key question remains: "Do we need Taylor Swift, or does she need us?" said Mall. "I think she doesn't need us, right?"

"And maybe we do her."