Why won't the Avengers help the "irrelevant" people?

So you saying that the US Army goes out and stop everyday crime?  That the FBI are taking on singular car-jackings?  Tony is talking about the pay grade of the Avengers themselves not how much the everyday person makes.  When a person says "That is above my pay grade," they mean that isn't their job.  It is for someone in a higher position.  Tony told Peter that the bank robbers was below the Avengers' pay grade because they go after the bigger guns.  And he gave the information to the FBI.  This was in the movie.  The heroes in the DCEU are more vigilantes and work either alone or with each other.  The MCU heroes, for the most part, work with the authorities and the government.  They let the world work on its own until something comes along that needs a superhero.  When they start acting like the DC heroes they get in trouble for doing so.