Having been recruited by Nick Fury as a means to protect our planet from what Thor called a higher form of war, the Avengers have saved both the world and the universe on enough occasions to gain something of a reputation for themselves across the entire length and breadth of the galaxy.
That being said, Black Widow confirmed an interesting plot point that the Marvel Cinematic Universe has never really touched on before. Earth’s Mightiest Heroes are definitely much stronger when they work as a team to form one cohesive superpowered unit, but Florence Pugh’s Yelena Belova tells her onscreen surrogate sister that not everyone views them as equals.
You can’t argue with the logic behind it, when Scarlett Johansson’s Natasha Romanoff and Jeremy Renner’s Clint Barton don’t have any special abilities of their own, they just happened to be S.H.I.E.L.D. agents that were very good at their jobs. Steve Rogers, Bruce Banner and Thor are all incredibly powerful beings, while Tony Stark is a genius billionaire playboy philanthropist with a technologically advanced suit of weaponized armor that even the brightest minds in the field of science have continuously failed to replicate.
It must sting for Natasha to hear Yelena dismiss Black Widow‘s status among the Avengers by saying she’s not “one of the big ones”, but the Red Room assassin goes on to make an even better point when points out that there’s no chance “the god from space has to take an ibuprofen after a fight”. It’s an interesting caveat as to how the team is perceived within the context of the MCU, and you’d imagine someone like Thanos would be much happier to have come up against a highly trained covert operative than someone like Wanda Maximoff or Captain Marvel, both of whom almost handed the Mad Titan his ass on a platter.