“Captain America: Brave New World” is flying into theaters on its opening weekend, weighed down by heavy rewrites and a muddled vision. A talented cast, computer generated images, and nostalgia leaves audiences longing for Marvel movies that left them cheering.

The new Captain America, Anthony Mackie — Falcon in previous films — does his best. The same goes for the man playing President Thunderbolt Ross, Harrison Ford, slowed to a sleepwalk at 82.

“Brave New World” shows the Disney-owned Marvel Cinematic Universe itself, not just audiences, suffer from superhero fatigue. Why they don’t bring to life the best comic book tales and adapt their storyboards is anyone’s guess.

Screenwriters could take lessons from Marvel’s legendary writer, Stan Lee, who understood characters and dialogue. He knew that heroes are not forged by armor, magical hammers, mutations, or shields.

By casting Mr. Mackie, a Black man, Marvel hoped for a fresh perspective. It was promising when Wilson said he was not worthy of Captain America’s shield when handed it by his predecessor, Steve Rogers.

During World War II, the super-soldier serum transformed Rogers into the Sentinel of Liberty. Wilson is just an ordinary man, but we’re informed that the serum is available and he makes the unwise choice to battle super-powered foes without it. 

Characters call Wilson by his new title so often it’s as if they’re trying to convince him and us that it’s so. It grates that many use the diminutive, “Cap,” too. Ross’s presidency inspires a similar lack of respect. 

Ross’s grudge against Wilson is never established and his Red Hulk persona is puny. “Since when are they red?” one reporter quips when a sane person would run for her life. 

On the “Brave New World” poster, the Red Hulk is punching Wilson’s behind the shield, but the hero seems annoyed rather than terrified. The subplot of Japan and America is just as implausible.

Wilson may have the shield, but his high-tech armor and weapons render it superfluous. It’d be nice to say it seems to feel as heavy as that star-spangled mantle, but we don’t get that or any other hero’s journey.

The director of 2011’s “Captain America,” Joseph Johnston, understood that the shield was for protection, a metaphor for America’s defense. “Throwing the shield was given a lot of thought,” he told IGN. Captain America did it “maybe four or five times, but when he does, it’s a big deal.”.

In Wilson’s hands, the vibranium disk makes more trick shots than Minnesota Fats; Mr. Johnston’s “highlight-reel moments” are reduced to the mundane. The new Falcon, Danny Ramirez as Joaquin Torres, faces far more exciting challenges than the titular hero. But no one buys tickets to see the sidekick.

The actor portraying Hulk’s nemesis, Tim Blake Nelson, looks sick rather than just mutated by radiation. He’s never called by his comics name, The Leader, and is reduced to a victim of the military with his metal powers reduced to those of an oddsmaker.

Carl Lumbly embodies Isaiah Bradley with more gravitas. The Black character first appeared in a 2003 comic, where he, too, is abused by the American military. In his case, it’s a parallel to the infamous Tuskegee Experiment, but it further confuses things.

Hollywood’s struggle with America as the good guys was made clear at Mr. Mackie’s press event in Italy. “For me,” he said, “Captain America represents a lot of different things, and I don’t think the term ‘America’ should be one of those representations.” He later declared himself “a proud American,” but the damage was done.

It could have been interesting to explore politics as Captain America did so in the comics. In 1974, he fought President Nixon during Watergate, lost, and became Nomad, the “man without a country.” 

“Brave New World” isn’t the serum to cure superhero fatigue. That won’t happen until studios wake up and realize that it takes more than big budgets to make audiences care, and more than a shield to be Captain America.