Ahead of the final episode of The Late Show With Stephen Colbert on CBS, former network late-night host David Letterman said that he would be “surprised” if other shows in that format last too much longer.

Letterman, 79, made the remark in an interview with the New York Times that was published on Tuesday, in which he also described his “disbelief” upon learning Colbert’s show had been cancelled.

Evidently alluding to nightly comedic talkshows hosted by Jimmy Kimmel on ABC as well as Jimmy Fallon and Seth Meyers on NBC, Letterman remarked the format was “not completely dead on arrival, but I would be surprised if it lasts more than a year or so.

“But it’s such an easy soothing format that it’s got to stay on.”

When pressed on whether he would truly “be surprised if late night survives another year or so”, Letterman responded, “Well, maybe specific shows. I don’t think it’ll ever go away because it’s just the best. It’s humans talking to humans.”

Letterman’s interview comes as the last episode of The Late Show’s 33-year run is scheduled to air on 21 May. CBS announced the show’s cancellation in July.

Executives at the time said that it was “purely a financial decision against a challenging backdrop in late night”. Yet, while advertising revenue across late-night shows has declined in recent years, the decision to cancel and reasoning around it drew skepticism from critics who have pointed out that at the time Paramount – CBS’s parent company – was finalizing a multibillion-dollar merger with Skydance that required the approval of the Trump administration.

And Colbert has been a vocal critic of Donald Trump across his two presidencies.

The cancellation also came days after Colbert criticized Paramount for settling a lawsuit with Trump for $16m (£12m) over claims that CBS News deceptively edited a 60 Minutes interview with Kamala Harris, his rival in the 2024 presidential election.

Colbert took over as host on The Late Show in 2015 after Letterman had hosted the show for 22 years.

Asked about CBS’s explanation that the cancellation was due to financial reasons, Letterman told the Times in Tuesday’s interview: “They don’t share the books with me. All of television seems to have been nicked by digital communication and streaming platforms and on and on. TV may be not the money machine it once was.”

Nonetheless, Letterman argued that Colbert and his employees deserved better – as did his fans who tuned in every night his show started at 11.30pm.

“What about the humanity for Stephen and the humanity of people who love him, and the humanity for people who still enjoyed that 11.30 respite?” Letterman said.

“He was dumped because the people selling the network to Skydance said, ‘Oh no, there’s not going to be any trouble with that guy. We’re going to take care of the show. We’re just going to throw that into the deal. When will the ink on the check dry?’

“I’m just going to go on record as saying: They’re lying.”

According to the Times, when asked to comment, a spokesperson for CBS said The Late Show’s cancellation was “unequivocally a financial decision”.