In 2015, the USA cable network was a force in original programming. Dramas like “Suits,” “Mr. Robot” and “Royal Pains” either won awards or attracted big audiences.

What a difference a few years make.

Viewership is way down, and USA’s original programming department is gone. The channel has had just one original scripted show this year, and it is not exclusive to the network — it also airs on another channel. During one 46-hour stretch last week, USA showed repeats of NBC’s “Law & Order: Special Victims Unit” for all but two hours, when it showed reruns of CBS’s “NCIS” and “NCIS: Los Angeles.”

Instead of standing out among its peers, USA is emblematic of cable television’s transformation. Many of the most popular channels — TBS, Comedy Central, MTV — have quickly morphed into zombie versions of their former selves.

Networks that were once rich with original scripted programming are now vessels for endless marathons of reruns, along with occasional reality shows and live sports. While the network call letters and logos are the same as before, that is effectively where the overlap stops.

The transformation could accelerate even more, remaking the cable landscape. Advertisers have begun to pull money from cable at high rates, analysts say, and leaders at cable providers have started to question what their consumers are paying for. In a dispute with Disney this year, executives who oversee the Spectrum cable service said media companies were letting their cable “programming house burn to the ground.”

“It’s kind of like when you drive by a store and you can see they’re not keeping it up, and it looks kind of sad,” said Linda Ong, a consultant who works with many entertainment companies and used to run marketing at the Oxygen cable network. “It feels like they don’t have the attention. And they don’t — they’re being stripped for parts.”

The media companies that own the channels are in a bind. The so-called cable bundle was enormously profitable for media companies, and more than 100 million households subscribed at the peak. But subscribers are rapidly declining as people migrate toward streaming.

Now roughly 70 million households subscribe to cable. As a result, most media companies are pulling resources from their individual cable networks and directing investment toward their streaming services. Peacock, which is owned by NBCUniversal, the same parent of USA, has begun making more and more original scripted shows over the last three years.

However, most streaming services are hemorrhaging cash. (An NBCUniversal executive said this week that Peacock would lose $2.8 billion this year.) Cable, though it is getting smaller, remains profitable.

Now, some industry insiders and analysts are questioning whether executives shifted too quickly and are limiting future revenue from distributors and advertisers.

“Unfortunately, they’re killing the golden goose,” Michael Nathanson, a media analyst, said of entertainment companies and the cable bundle. “Yes, maybe this demise was inevitable. But by putting more and more content in streaming, there’s literally nothing on cable.”

In 2015, there were at least 214 original scripted programs on premium and basic cable, according to programming records analyzed by The New York Times. By last year, that figure had fallen 39 percent, and it has fallen even more this year — partly, perhaps, because of the monthslong writers’ and actors’ strikes.

In 2015, TBS and TNT aired 17 scripted shows. This year, it has a total of three series, according to the records. Cable networks like Comedy Central, Freeform, A&E, History, MTV and Lifetime also air far fewer scripted programs.

Reruns are filling the hole. On a recent weekday, TBS played shows like “Friends,” “The Big Bang Theory,” “Modern Family” and “Young Sheldon.” Over at Comedy Central, there were “The Office” and “Seinfeld.” MTV had 20 consecutive hours of “Catfish: The TV Show.”

Cable executives say they have made programming moves that fit better in a diminished cable landscape — and, in many cases, cost less to produce.

A spokeswoman for NBCUniversal said USA had moved investment from scripted programming toward unscripted programming, library rights and sports. The channel’s live sports coverage includes the Premier League, NASCAR and Olympic events. Professional wrestling remains a backbone of the network, as it has been for many years.

Ratings in prime time are enough to keep USA as the No. 3 cable entertainment network, the spokeswoman said. She also noted that NBCUniversal did not sell advertising exclusively for USA but across many of the company’s brands.

A spokeswoman for TBS and TNT, two other top cable channels, pointed to the release of the second season of a British drama, “The Lazarus Project.” She said TBS and TNT offered various other scripted options for viewers, noting hits that were originally made for other channels, like “The Big Bang Theory,” “Friends” and “Modern Family.”

There are some exceptions among cable channels. Bravo, another NBCUniversal property and the home of the “Housewives” franchise, “Vanderpump Rules” and “Below Deck,” remains a culturally relevant force that has spawned a popular in-person annual convention: BravoCon. The Hallmark Channel has laid claim to the holiday season, spitting out one Christmas movie after the next, and has scored strong ratings. (Hallmark and Bravo shows also appear on Peacock.) The Paramount cable network was able to release a bona fide hit in recent years with “Yellowstone.”

But more common are the lineups at channels like USA. The original nonsports programming comes largely in the form of reality shows. This year’s programs include a celebrity bar-themed game show, “Barmageddon,” and a competition show, “Race to Survive: Alaska.”

It’s quite a departure from the upbeat, procedural programming that once defined the network — and the brand. Series like “Monk” and “Suits” were part of a strategy that included as many as 10 original scripted shows per year. (“Suits” has since found new life, setting streaming records this year on Netflix.)

Ms. Ong, the consultant and chief executive of Cultique, which advises entertainment companies, said she had recently visited the USA website. There was no mention of “Law & Order: Special Victims Unit” or “9-1-1” or “Shark Tank” or other network repeats that populate the network’s lineup day to day. There were, however, banners for some of the reality shows on USA, programs on Peacock and NBC, and other shows from cable networks like CNBC and Telemundo. The mishmash was reflective of the current state of the network.

“USA doesn’t have value beyond a television set right now,” Ms. Ong said. “There are some brands that have value beyond their existence as a linear network — Bravo has that. USA doesn’t.”

Mr. Nathanson, the media analyst, said that could spell trouble. Even as cord-cutting accelerated in recent years, advertisers mostly stuck with the cable networks. But last year, he said, was finally a “tipping point” — when advertisers began to look askance at nonsports cable programming.

Cable advertising revenue has decreased by double-digit percentages for five consecutive financial quarters, Mr. Nathanson said. He said he had never seen that outside a recession.

“Advertisers are starting to realize that there’s really nothing on here and they shouldn’t pay for it,” he said.