Spider-Man: Far From Home was Peter Parker's first step from being a high school superhero to being a true vigilante who must endure the consequences of his actions. In his second outing in the Marvel Cinematic Universe, the consequences came in the form of Mysterio, a bitter scientist who wanted revenge on Tony Stark for mocking his invention. Scared of never being heard, he created a hero with a group of equally disgruntled Stark employees and began to lie to the world.
Source：https://www.cbr.com/far-from-home-theory-mysterio-survived/
