Funnily enough, Tony ends up being the major reason Quentin Beck/Mysterio comes into Peter's life at all. Beck is a jilted scientist who once created highly advanced "illusion tech" for Stark Industries, which Tony was skeptical of and eventually dubbed "B.A.R.F." (short for Binarily Augmented Retro-Framing).
Beck was unsatisfied with Tony's choice to turn the tech into a device used by therapists (which you might recall in Iron Man 3), and a grudge was born. Beck later becomes the leader of a crew of Stark alums who team up to steal back some of the glory that they think was taken from them by Tony.