Norwegian family dramedy "Sentimental Value" won the prize.
In his speech, filmmaker Joachim Trier paraphrased African American author James Baldwin, who he said "makes us remember that all adults are responsible for all children."
"Let's not vote for politicians who don't take this seriously into account."
Top winner Paul Thomas Anderson said he made "One Battle After Another" -- the top winner with six prizes -- for his kids as an apology "for the housekeeping mess that we left in this world we're handing off to them."
"But also with the encouragement that they will be the generation that hopefully brings us some common sense and decency," he said.
And Pavel Talankin, the co-director and protagonist of "Mr Nobody Against Putin," said the world should "stop all of these wars now."
Billy Crystal -- himself a veteran Oscars host -- delivered a heartfelt tribute to his late friend and regular collaborator Rob Reiner, who was murdered along with his wife at their Los Angeles home late last year.
A crew of people Reiner famously worked with, including Meg Ryan, then appeared onstage.
FAREWELL TO THE GREATS
A lengthy In Memoriam segment was given ample airtime after a year that took a number of film legends with it.
A who's who of some of Hollywood's heaviest hitters who died in the last year were also honored, including Diane Keaton, Catherine O'Hara and Robert Redford.
The 83-year-old icon Barbra Streisand sang for her friend Redford, delivering a few bars from "The Way We Were" for her co-star in the film of the same name.
"Bob had real backbone, on and off the screen," said Streisand. "I called him an intellectual cowboy who blazed his own trail."
PROMO OPPORTUNITY
The Oscars were broadcast by the network ABC, which is owned by Disney, and organizers took the opportunity to advertise the studio's upcoming films.
While presenting awards, Sigourney Weaver and Pedro Pascal -- stars of this year's "Star Wars" film "The Mandalorian & Grogu" -- performed a bit that featured Grogu (also known as Baby Yoda) in the audience.
And Vogue doyenne Anna Wintour alongside Oscar winner Anne Hathaway delivered a humorous sketch that doubled as promo for the forthcoming "The Devil Wears Prada 2," to be released this spring.
Marvel cinematic universe stars Chris Evans and Robert Downey Jr. also reunited onstage ahead of the release of "Avengers: Doomsday" later this year.
CONAN'S JOKES
Host Conan O'Brien nodded to politics and pulled a few punches, some with global appeal and a few one-liners for the insiders.
"It's great to be back hosting the Oscars. Last year, when I hosted, Los Angeles was on fire. But this year, everything's going great," he joked, pausing for effect.
O'Brien also had a pointed industry remark for Netflix CEO Ted Sarandos: "It's his first time in a theater."
He also alluded to the Jeffrey Epstein drama.
"It's the first time since 2012 that there are no British actors nominated for best actor or best actress," O'Brien said. "A British spokesperson said, 'Yeah, well, at least we arrest our pedophiles."
"Marty Supreme" star Timothee Chalamet, who left empty-handed, also got a notable roast, as O'Brien took shots at the actor who recently disparaged ballet and opera.
