With so many teams within the Marvel universe, it's often argued which one is the best. But during an issue of What If...?, the Silver Surfer gives an answer as to how the Avengers are better than the Fantastic Four. The issue was written by Chuck Dixon with art by Joe Barney, Don Hudson, and Michael Kraiger.
In this alternate history, Silver Surfer doesn't betray Galactus. The turning point is when Reed Richards of the Fantastic Four is about to use the Ultimate Nullifier. Silver Surfer swoops in, steals the Nullifier, and gives it to Galactus instead. Without the threat of that weapon, there is nothing to stop Galactus from devouring the Earth and the Fantastic Four know it.
Reed is knocked unconscious, and rather than futilely trying to stop Galactus, Sue orders her brother Johnny and Ben Grimm to get inside the Baxter Building instead. There is a bomb shelter of sorts in there that will keep them safe while Galactus destroys the planet. The public goes crazy in fear, but the Fantastic Four cowardly lock them out. The only other person they allow inside is Alicia Masters. Unlike the Fantastic Four, the Avengers charge headlong into battle with Galactus. There's not much they can do. They are all wiped out pretty quickly. But at least the Avengers stood their ground to the very end, dying with honor rather than being scared and hiding like the Fantastic Four.
To add insult to injury, the Fantastic Four as a family ends up becoming Galactus's new heralds by the end of the story. Hiding away, the Fantastic Four weren't the only ones to survive Galactus devouring the world. Dr. Doom survives as well and heads into space with them to try to stop Galactus for a second time. While battling with the Silver Surfer, Doom actually sacrifices himself to destroy Galactus's herald. This leaves a vacancy for the job and the Fantastic Four are all too quick to swoop in and claim it for themselves.
Then again, this kind of behavior is fitting with the Fantastic Four's overall character, especially in their early days. Although the Fantastic Four do heroic deeds, they are known more a family of adventurers rather than a team of superheroes. So it makes sense that, when faced with the end of the world, the family would be interested in saving themselves rather than throwing their lives away. Still, if it weren't for the Silver Surfer, fans would never get to see how the Avengers are braver than the Fantastic Four.