Spider-Man has a long, complex, and intriguing history with the Avengers. Originally intended as an outcast and loner incapable of playing nicely with others, it seemed Spidey would never join the Avengers. This was captured in his first encounter with Earth’s Mightiest Heroes in The Avengers Vol 1 #11 (by Stan Lee, Don Heck, Chic Stone, Stan Goldberg, and Sam Rosen). After rescuing the team from an evil android Spider-Man sent by Kang the Conqueror, many fans no doubt hoped the Wall-Crawler would join their ranks. However, Spider-Man left the battle without so much as a conversation, capturing Peter Parker’s insecure, bullied characterisation at the time.
Source：https://www.cbr.com/why-the-avengers-desperately-need-spider-man-on-their-team/
