While Marvel Comics has been trying to make the Fantastic Four commercially successful again for many years, if the company really wants to save the legacy of its first heroes, it should simply kill the team off. The Fantastic Four formula worked for a while, but then became outdated due to the characters' inability to adapt to changing times and to resonate with new generations of readers.
Fantastic Four #1 by Stan Lee and Jack Kirby came out in November of 1961 and saved the then-fledgling Marvel Comics from bankruptcy. The series opened the way for Marvel's Silver Age and set the standard that many other iconic characters would follow, from Spider-Man to the Avengers. Kirby and Lee introduced the idea that being a superhero could be a curse or make you a freak — something that didn't happen in the best-selling superhero comic of the time, DC's Justice League. Fantastic Four laid the groundwork for a comic book that gave the psychology of heroism as much importance as the action. However, over the past few years, the team has slowly been shelved, to the point that Marvel canceled their book in 2014, after a direct order from former Chairman Ike Perlmutter due to the conflict with Fox, which owned the movie rights for the characters.
Luckily, Fantastic Four was relaunched in 2018, but four years after that the title is struggling in terms of sales. This is shown in the ICv2 sales rankings for February 2022, when Fantastic Four Reckoning War Alpha #1 came out. It seems that Marvel is unable to make its "First Family" successful again, and the reasons are painfully clear. Fantastic Four worked during the first couple of decades because the team still fit Marvel's mold of "superheroes with super problems." The family often did not get along, their personal lives clashed with their public roles as superheroes (the Fantastic Four do not have secret identities), and this kind of conflict made them relatable to readers. At some point, however, conflict became secondary in FF's stories: after all, a family cannot keep fighting for decades without separating. It's not a coincidence that the only member of the team who has experienced constant popularity with readers is Ben Grimm, the Thing, who is the most tormented of the bunch, the only one with real "super problems."
The biggest issue, however, is that the Fantastic Four are stuck in their well-established family dynamic, which prevents them from changing and adapting to the times. The roster of the Avengers or of the X-Men can change, as Marvel can bring in other heroes who are more compelling for readers, but the Fantastic Four always has to be Reed, Sue, Ben, and Johnny. Attempts to introduce new members over the years inevitably floundered, but that's the way to go if Marvel wants to save the Fantastic Four's legacy: not just change one member, but change them all. Have Reed and company die, or retire, and bring in a new team of Fantastic Four, fresh heroes who can tell modern and compelling stories, without forgetting what made the FF great in the first place. The idea of "family" served to make the Fantastic Four different from other teams such as the Avengers, but it's time to let another family take the spotlight, one with new problems and dynamics.
It should also be remembered that being a family is not the only thing unique about the Fantastic Four. They are explorers of the unknown, superheroes with no secret identities, and much more. Rather than trying to repackage the Fantastic Four again, Marvel should just realize that, as with any other team, their roster needs to change from time to time. It's true that the Fantastic Four represent Marvel Comics' history and origins, but that should not make them impervious to change, even if it means killing them to save their legacy.