The issue is that all the modern actors have emerged from the tongue-in-cheek Marvel franchise or similar. Tom Cruise almost exclusively plays dramatic roles (the only comedic role I can think of is the one where he's in Harvey Weinstein-esque prosthetics for Tropic Thunder) and he picks his roles very carefully. He dedicates 100% of his life not just to the movie he's in but to the role and mystique of the movie star which is at complete odds with social media marketing and trying to be a relatable person to get the public to like you.
Compare Cruise with Chris Hemsworth who's probably the closest thing to a bankable action star we've got right now (The Rock doesn't count because he essentially isn't acting, but is just playing the Rock in every movie). Chris Hemsworth makes some good movies but he doesn't choose the directors and projects he works on carefully the way Cruise did with Kubrick, Paul Thomas Anderson etc. Hemsworth is also out there hawking his fitness app, he's doing comedic bit roles and he relies quite heavily on his physique in a way that's closer to Stallone and Arnie. Cruise doesn't do any of these things because he knows that the more you see behind the curtain the less mystique there is. Hemsworth or an actor like him might raise his net worth by creating and selling his own whiskey but his value as a movie star declines when he does it - it cheapens him and his work, which have now become a vehicle to sell things outside of the movie. In contrast, Tom Cruise cares, above all else, in being a movie star. He dedicates himself to it not just inside the movies, but with his entire life outside of it too.
She's since changed, but there was a good interview with Lady Gaga on Johnathan Ross' talk show just after her first album came out. She was sat on the sofa in one of her extravagant costumes and Ross was trying to get her to admit that she went home afterwards and stuck her jogging bottoms on and her takeout stained t shirts and just chilled like the rest of us. Obviously it's true - you'll even see her in her casual attire around the house in her documentary. But at this point in time, pre-social media, Gaga refused to cave. She didn't want her fans to associate her with that - she wanted to be an embodiment, a symbol, an archetype, whatever you want to call it, of the elevated, mysterious pop star. Because that is what feeds the fanatic energy - people want their heroes to be bigger than them, to be above the drudgery of normal life, because that is what inspires them to dream bigger themselves. Tom Cruise is basically the last actor in the lineage of the mysterious movie star, dating right back to the early days of Hollywood with Charlie Chaplin, Buster Keaton and later, Clark Gable, Cary Grant etc where movies and moviemaking themselves were both novel, mysterious and glamorous.
Until Hollywood stops making every leading role an ironic tongue in cheek comedian and also stops with the relentless "we're just like you" YouTube video press machine, you won't get another Tom Cruise because Tom Cruise is the embodiment of the movie star archetype. Between the current crop of actors and the studios, none of them seem interested in going to the lengths necessary to craft the mystery, spectacle and otherness necessary for a movie star anymore.