On a Wednesday night in early March 1999, Barbara Walters invited a small group of friends and colleagues to her New York apartment to watch her two-hour interview with Monica Lewinsky. During a commercial break, Walters stood by the window, looking out over Central Park, and noticed something peculiar. “There’s no traffic on Fifth Avenue,” she observed.

“That’s because everyone is home watching the interview,” one of her producers said.

It was only a slight exaggeration. Nearly 50 million people tuned in to see Walters question Lewinsky, the former White House intern, about her relationship with President Bill Clinton, more people than had ever watched a news program — or have watched one since. As was often the case with Walters’ broadcasts during her prime, it was television as a form of national theater.

On Friday, the 84-year-old Walters signed off from her ABC daytime show “The View” for the last time. After five decades in television, the woman who started her career on camera as a pitchman for Alpo dog food and went on to cross the Bay of Pigs with Fidel Castro and to interview every U.S. president (and first lady) since Richard Nixon is retiring.

As the sun sets on Walters’ career, it is also setting on the form of television news she perfected and personified: the intimate sit-down with a world leader, the weepy celebrity confessional, the jailhouse interview — the so-called “big get.”

In her final weeks on the air, when the disgraced Los Angeles Clippers owner Donald Sterling was the man of the hour, Walters interviewed his girlfriend. About 7 million people tuned in. V. Stiviano is no Lewinsky, but the disparity in ratings says as much about the changed media landscape as it does about the interviewees’ relative star power.

Walters’ peers can’t help but see her departure as more than the end of one woman’s career.

“With Barbara’s retirement, so goes TV news,” said Connie Chung, a longtime television news anchor. “There’s no big payoff for an exclusive television interview with someone for an hour. No one is going to watch it, anyway.”

Walters did not invent the celebrity get. That distinction belongs to Edward R. Murrow and his 1950s show, “Person to Person.” But Walters turned the celebrity interview into a kind of art form. She was unthreatening enough to land the big names, but probing enough to retain her journalistic credibility.

For decades, this was how we came to know presidents, world leaders and movie stars: in an upholstered chair, facing Walters or one of her imitators. Subject and interviewer would share in the reflected glory, increasing the celebrity of both newsmaker and newscaster.

But the power of the Big Three networks has faded. The demise of appointment viewing and the proliferation of alternatives to network news have obviated the need for a correspondent with great hair to come into a celebrity’s living room to take a confession. And how much value is there in an “exclusive” when people can follow the interview in real time on their phones via Twitter, or watch the highlights later on YouTube?

People in the business of both wrangling and advising celebrities say it is hard to imagine a single newscaster again holding so much sway over the culture.

“There is no one biggest, most important anything anymore,” said Leslee Dart, a publicist who has represented such stars as Woody Allen and Meryl Streep. “We just don’t live in that kind of media world anymore.”

For celebrities and their publicists, the fragmentation of the media has made life both harder and easier.

They no longer have the possibility of one-stop shopping — score that interview with Walters, and your media campaign is basically done — but they do have more outlets from which to choose. They can target a particular demographic, as President Barack Obama did when he appeared in March on the popular online comedy show “Between Two Ferns” to encourage more young people to sign up for health insurance.

Celebrities can also go straight to their fans. When Gwyneth Paltrow “consciously uncoupled” from her husband, Chris Martin, she did not sit for an emotional television interview. She made the announcement — in her own words — via her website, Goop. The post brought so much traffic to Goop that it crashed.

The very notion of a celebrity choosing to break news in an interview could soon become outdated. A lot of younger stars simply keep their fans updated on their ups and downs via social media.

But for disgraced celebrities trying to redeem their reputations, submitting themselves to rigorous questioning is still the recommended course of action. That is how ABC’s Bob Woodruff landed John Edwards in 2008 and how Oprah Winfrey landed Lance Armstrong last year.

It is also how Walters landed V. Stiviano, and Sterling’s wife, Shelly.

Of course, by the time these exclusive interviews were shown, the Sterling scandal had been playing out on the Internet for days. And it was not Walters but CNN’s Anderson Cooper who scored Sterling himself. It was the biggest get of the whole sordid affair, even if only 720,000 people were watching.