Re: MCU: Phase II - Part 2
Without the build up of the previous MCU movies, Avengers would've been like X-Men. Audiences would've automatically seen them as a team (even if they're coming together for the first time) and not individual heroes in their own right. They would always have that team association about them and not separate all-star heroes coming together for an event.
It's not like the general audience see Wolverine, Professor X, Storm, Rogue, Cyclops, Jean Grey all teaming up together to fight a common enemy. They're just seen as one unit. Same with the Fantastic Four. People wouldn't have even necessarily remembered all the team members of the Avengers, just that one seemed cool to them.
Anne Hathaway: "You did not just ask me that!! What a forward young man you are!!! My goodness!!"