Paul Rudd, left, and Jonathan Majors in “Ant-Man and the Wasp: Quantumania.” Jay Maidment/Marvel Studios

“It’s never over.”

Those prophetic words are spoken by Kang the Conqueror in “Ant-Man and the Wasp: Quantumania,” but they apply just as easily to the Marvel Cinematic Universe, the pop culture behemoth that has self-iterated into infinity, wiping out what used to be called “movies” and co-opting an entire medium for generations to come.

Reportedly, “Quantumania” is part of the MCU’s Phase 5, which – OK. Is anyone really still keeping track? Since “Avengers: Endgame,” the new installments have sought to introduce new storylines and characters to keep the vibe alive (also known as maintaining billion-dollar profits), with mixed success. Here, we meet Kang, played with mournful menace by the superb Jonathan Majors. But his Shakespearean gravitas feels woefully out of place in one of the Ant-Man movies, which, with their cheerful, wholesome tone, have been the most little-kid-friendly offshoots of the ever-growing “Avengers” sequoia.

In “Quantumania,” sprightly pacing and lighthearted humor have succumbed to the turgid seriousness that plagues so much of the comic book canon. Granted, Paul Rudd still projects irresistible likability as Scott Lang, the onetime thief who as Ant-Man is the tiniest member of the Avengers team. As “Quantumania” opens, Scott is reading from his new memoir, “Look Out for the Little Guy,” in a cheeky montage set to the theme from “Welcome Back, Kotter.”

Michael Douglas, Michelle Pfeiffer and Evangeline Lilly in “Ant-Man and the Wasp: Quantumania.” Jay Maidment/Marvel Studios

So far, so adorable. But soon enough, Scott; his daughter, Cassie (Kathryn Newton); his girlfriend, Hope (Evangeline Lilly); and Hope’s parents, Hank Pym and Janet Van Dyne (Michael Douglas and Michelle Pfeiffer), are plunged into the Quantum Realm, a secret universe “outside time and space” that has been seemingly populated by psychedelic bathtub toys and constructed from the remnants of vintage Yes album covers (ask your grandparents).

The plot – which is very plotty – is beside the point in “Quantumania,” which pulls from a variety of sources for both its themes and its visuals. On-trend subjects like the multiverse and hegemonic tyranny come in for comment and critique; the production design grabs snippets from the “Star Wars” cantina scene and reaches back to Ray Harryhausen, Japanese kaiju and “King Kong” for inspo in the final showdowns. All of the actors acquit themselves with dignity amid the outlandishness: Pfeiffer’s Janet turns out to be a chief protagonist in a story that delves into her past in the Quantum Realm. Still preternaturally beautiful, Pfeiffer strides through the spaceship rides, dingus battles and inevitable climactic faceoff with the same coolness she brought to the zonked-out femme fatale in “Scarface.” The film’s biggest cameo falls awkwardly flat; as heartening as it is to see William Jackson Harper play a Quantum Realm rebel, he’s largely wasted in a film that’s less interested in character development than in action beats and deliverables.

“Quantumania” will most likely work as dutiful, if not particularly original, fan service. But for those of us who still crave films about recognizable human beings, there’s something dispiriting about watching such gifted actors legitimize yet another generically familiar sequel. The disconnect is particularly obvious watching Rudd – a brilliant comic actor and hugely appealing leading man – spending most of “Quantumania” running and yelling amid green-screen fakery and CGI filler.

The endearing sweetness of the early “Ant-Man” movies, which tapped Rudd’s ineffable charm, has been bigfooted into a noisy, smash-and-grab extravaganza that, for all its self-conscious bigness, feels smaller and less ambitious than its predecessors. It’s never over. But it could be better.