"There are so many aspects of this film that ask so many fundamental questions that I think many of us will be wrestling with, especially now," said Clarke.
"I think it's timely, important and beautiful."
While Sundance skews to low-budget films, Clarke is one of dozens of Hollywood stars who will make the trek to Park City for high-wattage premieres.
Also Thursday, "Star Wars" alumnus Daisy Ridley unveiled "Sometimes I Think About Dying," a low-key indie drama in which she plays a deeply shy office worker whose quiet life is punctured by the arrival of a new, charismatic colleague.
On Friday, Jonathan Majors will unveil a much-hyped performance in "Magazine Dreams," set in the dangerously competitive world of amateur bodybuilding.
At the weekend, Anne Hathaway stars in "Eileen," about a young secretary working at a prison who befriends a glamorous counselor with a dark secret.
Emilia Jones also returns to the festival that first played her best picture Oscar winner "CODA," with "Cat Person," adapted from a New Yorker short story, and "Fairyland," based on a best-selling memoir about San Francisco's AIDS crisis.
Despite -- or because of -- headwinds now facing the market for films aimed at adults and arthouse movie theaters, anticipation for Sundance's return this year has been especially high.
"It's just exciting to be back at the mountain," said Sundance CEO Joana Vicente at a press conference Thursday, referring to the festival's ritzy ski resort home.
Program director Kim Yutani said Sundance stands out from other festivals with countless examples of "directors getting their next gig, or people meeting their next collaborators on the shuttle" between venues.
Director Nicole Newnham -- whose previous Oscar-nominated documentary "Crip Camp" debuted at the last in-person festival in 2020 -- told AFP it felt "surreal" to be back.
Her latest documentary "The Disappearance of Shere Hite" tells the astonishing but forgotten story of the author of "The Hite Report" -- a pioneering survey on female sexuality that sold millions of books but triggered a furious backlash from conservatives.
It is one of several major documentaries this year tackling sex and politics, along with "Judy Blume Forever," which charts how the US author guided a generation of young girls through puberty, but also came under attack from activists.
Brooke Shields will attend Sundance as the subject of "Pretty Baby," which addresses the sexualization of young girls via the supermodel's own journey.
"I'm really honored to be included in the festival this year... the fact that there's such a strong showing of films about women's sexuality and women's issues is really heartening," said Newnham.
On Friday, Jason Momoa narrates "Deep Rising," an eye-opening and unsettling look at the race to harvest the ocean seabed for rare metals under the guise of furthering the "so-called green revolution."
Other timely and prominent themes in the documentary lineup include films about Ukraine and Iranian women.
The 2023 Sundance Film Festival runs until 29 January.