“Ant-Man and the Wasp: Quantumania” launches Phase 5 of the Marvel Cinematic Universe, but these phases are starting to feel like variants in a pandemic.

The storylines in every MCU phase depend on leaders heading in the wrong direction, unintentionally, and then fighting their way back to a new normal that may no longer exist (is everything a pandemic metaphor?). But it’s discouraging to see the friskiest MCU franchise swell up like a tick in terms of its reported $200 million production budget and its universe-destroying threat levels while shrinking in effectiveness.

“Ant-Man” (2015) was fun; “Ant-Man and the Wasp” (2018) was fun, too. “Quantumania,” again directed by Peyton Reed, is less fun, and blandly garish visually. The earlier films’ throwaway jokes and welcome aversion to brutal solemnity have largely been ditched in favor of endless endgame stuff and weirdly cheesy digital world-building in the Quantum Realm.

Paul Rudd is back as Scott Lang/Ant-Man, as is second-billed Evangeline Lilly as Hope Van Dyne/Wasp. Second-billed implies a certain portion of the action and the talking, but Lilly is practically mute in “Quantumania,” and you keep waiting for some explanation for this. A curse? A character grudge we’ll eventually find out about? Aside from the occasional boilerplate, Hope’s strictly sideline material.

The plot this time sends Scott, Hope, Hope’s parents (Michelle Pfeiffer and Michael Douglas) and Scott’s enterprising and socially conscious daughter, Cassie (Kathryn Newton), into the sub-universe of Quantumville. Aside from bookend sequences set in San Francisco, the sloggy whole of “Quantumania” takes place there, in a land of reputed magical visual wonders that look like leftovers from Pandora after being reheated on high in a bowl with reruns of “H.R. Pufnstuf.”

Question: How to get back home? Conflict: Why is Kang the Conqueror (Jonathan Majors) trying to kill us and destroy all worlds? Well, he’s a supervillain, and we’ve seen his like before (in a related guise on Disney’s series “Loki”). We’ll be seeing him again, of course, since Majors is a fascinating actor.

Usually, that is. It depends on the material, as it does for every actor, and here, Majors spins his wheels trying to make this supervillain his own. Always a thinker on screen, Majors makes a rare error in dramatic strategy in “Quantumania,” trading dramatic pauses for momentum and pacing. After an hour, a lot of the lesser MCU movies start to feel like green screen jail, for everyone on screen as well as the audience.

Director Reed, forced by the script to lean into the combat melees, still has his ace in the hole, which is Ant-Man and company’s ability to change size in a blink, going from ant size to Iron Giant size when needed. The movie is not awful, but the kinetic battles are chaotic, and the look of the Quantum Realm is oddly drab in its interweaving of digital and VFX elements, seeming at times to be more like several first drafts of a new “Star Wars” franchise instead of a natural extension of this one. Midway through, as everyone on screen was restating their interest in getting home again, I thought: Same!

Still, not all is lost. “Quantumania” introduces the scowling, fearsome, highly screenworthy revolution-leading warrior, Jentorra, portrayed by Katy O’Brian. She’s a beast, the best kind, and ready for anything — even when the film itself isn’t much of anything.

MPA rating: PG-13 (for violence/action and language)

Running time: 2:05

How to watch: In theaters