Spider-Man 2 only improved on the original. The latter sequel is considered one of the best examples of the genre period, but 2007's Spider-Man 3 would end the trilogy on a down note.
There are several reasons for this, including producer interference and studio mandates. Venom was incredibly popular with comic readers, but Raimi never particularly liked the recurring villain. Regardless, he was forced to include Eddie Brock/Venom, in a story that was already balancing too many characters. There are great moments contained within Spider-Man 3, such as the "birth" of Thomas Hayden Church's Sandman, but the movie often collapses under the weight of too much plot. The sequel's handling of Venom is a common complaint in of visual design, his utter lack of menace and the fact he turns up too late.
Even the contrivance of having Topher Grace's Brock just happening to be in the same church as Spider-Man when he rips off the Venom symbiote is too much. One storyline Spider-Man 3 had to pay off was Harry Osborn seeking revenge for his father Norman's death. Harry wrongly believes Peter Parker/Spider-Man murdered Norman, and during Spider-Man 3 - which also retconned Uncle Ben's death - sets out to ruin his former best friend's life as New Goblin. The Harry story is one of the strongest parts of the sequel but the movie missed a trick by not having Venom infect Harry instead.
Venom Harry Could Have Tied Spider-Man 3's Story Together
While Eddie Brock plays a key role in Spider-Man 3 in of being Peter's rival and bringing out his darker side, Brock's late switch to main villain in the finale feels too rushed. As mentioned before, the fact he happens to be in the church to get infected feels too neat in story too, but a rewrite removing Eddie and having Harry take his place would make more sense. Following a confrontation midway through Spider-Man 3 that leaves Harry Osborn scarred by one of his own bombs, the story could have emphasized Harry's growing madness and fury. As New Goblin, he could have tracked Spider-Man down to the church when he rips off the symbiote, where it could have taken over Harry instead.
Giving Harry the power of Venom would have made the final battle much more personal too. The ending of Spider-Man 3 ends on a tragic note as Harry redeems himself and helps Peter defeat Venom, but dies in the process. The Harry as Venom ending could have functioned in the same way, but with Harry realizing his mistakes and dying as he pulls the symbiote off himself. It appears the filmmakers behind Spider-Man 3 - which got some elements of Venom right - never considered this an option, and probably felt having three unique villains would be a selling point, as opposed to having Harry become both New Goblin and Venom. Making this change wouldn't have fixed all of Spider-Man 3 issues, but in thematical and story , it could have made Venom a more organic part of the story.
