The original Spider-Man was greatly bolstered by the fact it was released a year after 9/11, as it provided for audiences a fun, colorful tone that served as nice escapism from the dire uncertainty of the times. Much like like how the original Star Wars was so popular because it came off the heels of the Vietnam war, and it provided audiences a feeling of jubilant escapism away from the darkness of the times. Spider-Man 2, while a great classic film, didn’t have the attractive hook to drive audiences this time around, the novelty of seeing Spider-Man on the big screen had worn off by then.
With Spider-Man 3, that attractive hook for audiences was the immense popularity of Venom, and how much hype there was seeing those two characters spar with each other in live-action for the very first time. Not to mention the cool and mysterious black suit Spider-Man which intrigued mainstream audiences, and played the factor in getting them curious about the movie. Spider-Man 2, didn’t really have either of those factors going for it and so it’s the least successful.