Turner Classic Movies host Ben Mankiewicz once walked the red carpet at an American Film Institute event in Hollywood and found himself standing next to director Steven Spielberg.

Mankiewicz looked down, trying to avoid fanboy eye contact. But then Spielberg said to the host, "Oh, my God, I love all your movies."

It's become part of life for Mankiewicz, who joined TCM 17 years ago and has encountered stars and filmmakers offering similar sentiments ever since. "Mostly people want to say thanks," he said.

Such are the perks of being on a cable channel with one of the most devoted audiences in television. The Atlanta-based TCM has long been the sanctuary of classic film on TV, presenting mostly pre-1980 movies commercial-free with a deep respect for moviemaking history going back to the silent film era.

TCM has managed to stick to its mission through shifting ownership of its parent company, WarnerMedia, which next year is expected to be spun off and merged with Discovery Inc. While current owner AT&T made its influence felt across WarnerMedia's units, TCM has gone largely untouched and its ad-free format has been maintained, a relief to fans.

"TCM amongst filmmakers is considered holy ground," said director Paul Thomas Anderson. "Politically neutral, essential and unimpeachable in its dedication to film history. There is nothing like it and it should be protected."

Anderson admits to having TCM on a TV set in the kitchen of his home 24 hours a day. "I'm always afraid I'll miss something," he said. "It's a bottomless pit of inspiration."

But surviving as a traditional TV outlet in the current media landscape won't be easy for TCM. Viewers who want classic movies of all genres can access them on demand through a variety of streaming services, or even find them on YouTube.

TCM also faces the same pressure squeezing all cable channels — every month thousands of U.S. homes are dropping their pay TV services. For TCM, it has meant a loss of subscribers. The channel was available in 68.2 million homes at the end of 2020, down from 73.3 million in 2019, according to Nielsen.

TCM's commercial-free status is a key reason viewers embrace it. The downside is it cannot raise ad rates to offset the revenue decline caused by cord-cutting. S&P Global Intelligence data shows the network took in $286 million in subscriber revenue in 2020, down from $313.6 million the previous year.

"I fear for the future of TCM," director Martin Scorsese said. "So does everyone else I know who loves movies."

Scorsese will keep TCM on one of the screens in his editing suite while he's working.

"It gives me something to turn to, to bounce off of, to rest in, to reinvigorate my thinking — just glancing at some image or combination of images at a certain moment," he said. "It's more like a presence in the room, a reminder of film history as a living, ongoing entity."

"The Godfather" director Francis Ford Coppola, another devoted fan, said he is still discovering titles on TCM after a lifetime of movie viewing.

"I recently saw a film I never heard of starring John Garfield — 'He Ran All the Way,'" Coppola said. "And I realized that I never appreciated what a great actor he was until I saw his work in this, his final film. It would not have come to my attention if not for TCM."

TCM launched on April 14, 1994, with a ceremonial screening of "Gone With the Wind" in New York's Times Square. It became the preeminent brand for vintage classic film over the next 27 years.

"We created a world that people wanted to come into all the time and we didn't assault them with commercials," said Brad Siegel, a former Turner executive who ran TCM when it launched.

For some viewers, the channel serves as a curator through Hollywood's storied past. For others, it's a comforting escape from present-day reality.

Despite challenges, TCM does have an advantage over other entertainment channels. By depending on film libraries — many of the 16,000 titles it can draw on are owned by its parent company — TCM is less vulnerable to rising programming costs. WarnerMedia does not disclose financials for TCM but, according to Siegel, the channel has delivered strong profits since its launch.

TCM also appeals to an older audience that is more likely to hold onto its cable subscription than younger viewers who quickly adapted to streaming platforms. The channel also connects with fans through live events, cruises, books, an annual film festival and even a wine club.

Pola Changnon, general manager for TCM, said internal research shows the channel is keeping some subscribers from cutting the cord.

"We hear plenty of people say, 'Do I need all those other channels I don't watch?'" she said. "But at the end of the day, they really want and desire TCM, so they are going to stay with cable as long as we're there."