How many times have you sat down to watch a TV show and thought: That should have been a movie?

It’s a phenomenon particular to streaming originals, where an idea suited for a two-hour movie is stretched to fill a six to 10 episode season, if not multiple seasons.

I often find myself watching a series and thinking: Interesting premise — for a movie. But there’s not enough story or character development here for a multi-episode series. The results are often bloated and stalling for time, robbing the show of any sense of pacing.

In just the last month: “Severance,” Apple’s high concept workplace dystopia? Great concept. Shoulda been a movie. Or as someone on social media described it: “What if the first act of ‘Being John Malkovich’ wasn’t funny but was eight hours long?”

The return of Netflix’s action-thriller “The Night Agent”? Shoulda been a movie. Another action-thriller on Hulu called “Paradise”? Shoulda been a movie.

There’s a running joke in “Paradise” that references “Die Hard,” which inadvertently underscores the truism that if “Die Hard” were an eight-episode series instead of a movie, it wouldn’t have worked half as well — and it wouldn’t be the pop cultural touchstone that people remember and rewatch decades after its initial release.

Apple tried it anyway two years ago with Idris Elba in “Hijack,” which was “Die Hard” in a plane. I have no issue with that premise or the eternally watchable Elba. But it didn’t need seven episodes — it certainly didn’t need the second season renewal it also got — because it never became more interesting or complex during its overly generous running time. It just became longer.

That’s true of the Amazon adaptation of James Patterson’s Alex Cross character, which has a terrific star in Aldis Hodge. Shoulda been a movie. (And was a movie three times over in an earlier era.) Apple’s adaptation of Scott Turow’s “Presumed Innocent” starring Jake Gyllenhaal? Shoulda been a movie. And it was. In 1990. Both shows have been renewed for a needless second season.

Bridgett M. Davis is a professor emerita at City University of New York’s Baruch College. She is also a memoirist, screenwriter and director. Her 1996 film “Naked Acts” was rereleased last year.

“The beauty of film is really distinctive,” she said. “You go into it with a specific time horizon — both within the film and within the viewer’s experience — so the viewer knows that it’s all going to come to a head at the end of two hours. That’s what distinguishes it as an art form. If you are watching a TV series, you’re coming to it differently. So when I’m teaching screenwriting for film specifically, I’m saying, ‘You’re going to drop people into a world and take them on a finite journey. It’s a one-off experience.’”

Film characters function differently than TV characters. “If it’s a really well-written script, a film character shows you who they are in the first few seconds. Whereas a TV character can be about expansion — you’re learning, over the course of the season, all the ways this character can grow and change. And I don’t think enough writers understand the distinction. You might have a really cool idea for a character, but that character needs to be richer and much more complex in a TV series.”

Too often, shows resort to variations of the same beats and themes to fill the episode count. “Because the show creator came up with a premise that’s really a film idea,” said Davis. “They’re searching and scrambling. You have a film character that’s getting dropped into an expansive format, and they’re getting lost in it.”

She mentions the 1991 movie “Thelma & Louise” starring Susan Sarandon and Geena Davis and “that great opening where you ‘get’ who they are right away.” The middle portions resemble a buddy movie, and imagine, I said, if their misadventures were extended to fill a TV series — and then at the end of three seasons, they drive off the cliff in the series finale. “It would be torture! Also, there’s a power to the tight time frame of a movie.”

I have some theories about why this is happening. The movie industry has cratered and aside from blockbusters and art house films, studios aren’t releasing the kind of mid-budget titles in theaters that used to make up the vast middle ground. Which means all those great movie ideas have no place to go. Writers want to sell their work — understandably — so it’s possible they’re repurposing movie ideas for TV, where they have a better shot at getting greenlit.

The business model of streaming is also radically different from that of theatrical movie distribution. Streamers want to keep you watching as long as possible. It’s easier to do that with a series viewers are invested in. But too many shows fail to reward that viewer investment because they don’t understand television as a form. Some audiences will stick it out anyway. I’d wager many more bail long before the season is over. Completion rate is a data point that’s important to streamers, but they don’t make those numbers public. If we’re speculating why, maybe it’s because they’re so low.

On social media, the filmmaker Dan Mirvish, co-founder of the Slamdance Film Festival, said there was something else going on as well: “Hollywood is being driven by agents who know there’s way more money (for them) in streaming series. So the motive for screenwriters is to stretch out premises from a feature to series.

In older days, it might be feature first, then maybe spin-off to series.”

In other words: Selling a series, and the percentage a show creator’s reps collect over the life of the series, adds up to more than the percentage reps take get when a film script is sold. That’s true even if the average streaming show ekes out two seasons at most.