The thing I like most about the Avengers is seeing how the different characters interact with each other. There's characters from ancient mythology, like Hercules or Thor, interacting with more modern sci-fi characters like Ironman, the Hulk, or the Vision; there's the specialists ranging from Hawkeye to Dr.Strange interacting with mutants and superheroes, and every character has their own unique back-story and perspective. It makes it feel like, whoever's on the team, they're at the very center of an extremely diverse and extraordinary world; one with a rich and colorful history, where tomorrow can happen every day. How all of these different characters relate to that world, and to each other, makes for way more fun stories than any of them acting on their own.
What I don't like about the Avengers is when the stories have almost nothing to do with the characters, Hickman.