Not even the charms of Bradley Cooper and Emma Stone could guarantee box office success for Cameron Crowe’s “Aloha.” (Neal Preston/Sony Pictures Entertainment via AP)

Here’s an easy one: What do George Clooney, Johnny Depp, Reese Witherspoon, Adam Sandler, Mila Kunis, Hugh Jackman and Bradley Cooper have in common?

They’re some of the highest-paid hotshots in Hollywood, of course.

But they’re members of another group, too — paragons of Tinseltown nobility, who have headlined some of the biggest box office flops of the year. And they’re not the only A-listers who have failed get moviegoers to theaters. A year of high-profile bombs that kicked off with “Mortdecai” and “Jupiter Ascending” has culminated in a few more failures in the last couple weeks. “By the Sea” barely made a splash despite the star power of Angelina Jolie and Brad Pitt; “Our Brand Is Crisis” tanked, even though it starred Sandra Bullock; and this past weekend, the combined wattage of Julia Roberts, Nicole Kidman and Chiwetel Ejiofor wasn’t enough to get audiences interested in “Secret in Their Eyes.” The movie’s $6.6 million box office failed to reach even the studio’s ultra-conservative predictions.

It isn’t always an actor’s fault if his or her movie doesn’t click with audiences. After all, no one is going to blame Emma Stone for “Aloha.” (That was clearly Cameron Crowe’s mess.) It usually takes a village to ruin a movie.

[How Cameron Crowe out-Crowed himself with ‘Aloha’]

But the fact that 2015’s biggest debacles featured so many high-profile stars begs a question: Why do studios put so much faith in big-name actors when they clearly aren’t reliable money-makers?

The belief that a movie is only marketable if it has a major star is antiquated but also stubbornly commonplace. Look at Ridley Scott’s explanation for his casting choices in “Exodus: Gods and Kings,” for example. When people complained that all the Egyptians were played by white men, the director explained to Variety: “I can’t mount a film of this budget, where I have to rely on tax rebates in Spain, and say that my lead actor is Mohammad so-and-so from such-and-such. I’m just not going to get it financed. So the question doesn’t even come up.”

Sure, Scott is passing the buck, but he has a point: Studios are clinging to an old paradigm. Investors shy away from movies without a household name attached, which is why Scott cast Christian Bale and Joel Edgerton to play Moses and Ramses.

The punchline? The movie brought in only $65 million domestically. And while it did better abroad, ticket sales weren’t enough to recoup the $140 million budget plus marketing costs, according to Hollywood Reporter.

[‘Gods of Egypt’ promo posters reveal no lessons learned from ‘Exodus’ fiasco]

This should be a teachable moment, but most studios aren’t learning anything from the mounting evidence. They just keep looking backwards.

Not that long ago, actors were enough to sell tickets. People used to say they were heading to “the new Tom Hanks movie,” as if the star of a film trumped the subject matter. But we don’t talk in those terms anymore. No one calls “Jurassic World” “that Chris Pratt movie.” If anything, it’s “the dinosaur movie,” and if another actor had been cast in the lead role, the blockbuster would have just as easily crushed the competition.

Part of the shift is that stars don’t have the mystique they once did when our access to them was more limited. If we wanted to get our Eddie Murphy fix, we had to see his new movie, watch an old one on VHS or maybe luck out with cable. (And not so long before that, cable and VHS didn’t exist, so people who wanted to see John Wayne or Marilyn Monroe just had to buy a movie ticket.)

But our relationship to celebrities has changed. We have more ways to see stars than ever — and not just because the paparazzi is supplying us with images of Robert Downey Jr. grocery shopping. Big-time actors still appear in movies, but now the ads for those movies bombard us on multiple fronts. And in case we aren’t already getting enough of our favorite actor’s mug, we could probably find his or her complete filmography streaming somewhere.

And then there’s all the press. Who maintains their mystique with so many junkets and interviews, answering the same questions again and again (and occasionally making a flub and starting a Twitter uprising)? Who can still fascinate us after swapping mouths with Jimmy Fallon?

Plus, studios themselves have made actors seem replaceable. If one star doesn’t succeed in a role, rather than dream up a new story, the standard thinking is to order a reboot with a fresh face. When Matt Damon was done playing Jason Bourne, Jeremy Renner stepped in, and the high-stakes world of black-ops kept spinning. (And now Damon’s coming back.) When Tobey Maguire aged out of playing Spider-Man, Andrew Garfield became Peter Parker, and now — just moments later, it seems — Tom Holland is taking his place.

If there’s one studio that seems to understand the shifting interests of moviegoers, it’s Universal Pictures, which is killing the competition during its best year ever (and without a single superhero movie). This is the studio that brought us box office juggernauts, such as “Straight Outta Compton” and “Fifty Shades of Grey,” neither of which had household-name casts, plus “Jurassic World,” “Pitch Perfect 2” and “Trainwreck.” These movies didn’t star the highest profile actors, nor did they cater to the audiences that studios have so insistently aimed for — young white men.

In recent months, the gender pay gap has dominated the conversation in Hollywood. Actresses need to be paid more, the thinking goes, so they’re making the same salary as their male counterparts. But maybe people are coming up with the wrong solution to the problem. Men and women should be making the same amount for the same work, of course, but what if they’re all being paid too much? Why should a studio spend tens of millions of dollars employing an actor who can’t ensure a big box office? That’s simple. It shouldn’t.

More movie news: