The Avengers movies, by design, have escalated the expectations for a traditional Marvel movie.
Age of Ultron added several key figures who are still important to this day in Scarlet Witch (Elizabeth Olsen) and Vision (Paul Bettany) — core Avengers since the team’s earliest days.
By the time we reach Avengers: Infinity War, we’re at a ridiculous point where Spider-Man (Tom Holland) collaborates with Doctor Strange (Benedict Cumberbatch) and the Guardians of the Galaxy to fight Thanos (Josh Brolin) on Titan.
Joss Whedon’s first Avengers film gets proper credit for finally uniting Earth’s Mightiest Heroes for a battle against Thor’s step-brother, Loki (Tom Hiddleston), though it was in that movie that we got a tease of Thanos, pulling strings from afar.