Sam Raimi's original Spider-Man is one of the films credited with causing the boom in superhero movies that we are experiencing today. It was the wall-crawler's first time on the big screen and for many it was exactly what they had been waiting for.
Things only got better when Spider-Man 2 came along, a film which many at the time thought was an improvement on the original. However, a lackluster third installment, combined with script issues, let to a planned fourth film stalling out and never being made. While it's been over a decade since that movie died, Sam Raimi says he still thinks about the movie that could have been quite often. According to the director...
I think about it all the time. It’s hard not to, because each summer another Spider-Man film comes out! So when you have an unborn one, you can’t help but think what might have been. But I try to focus on what will be, and not look into the past.
It's certainly understandable that Raimi would tell Yahoo he thinks about this movie a lot. It would be one thing if your Spider-Man idea fell apart, and then you just moved on with your life. However, the fact that Spider-Man 4 didn't happen only resulted in the complete reboot of the franchise into a pair of Amazing Spider-Man movies, which were then rebooted again into the Marvel Cinematic Universe version we have today.
Between the last two Avengers movies, Into the Spider-Verse, and the recent Spider-Man: Far From Home it certainly does seem like the character is showing up every summer. You can add the stand alone Venom movie to that, as it probably reminds Sam Raimi of Spider-Man 3, which then leads to memories of the follow up that never happened.
While Spider-Man 3 wasn't as critically loved as the previous installments, it had no problem making money, and that meant that plans were quickly underway for another entry in the franchise. The plan, as far as is known, would have starred Vulture as the main villain. The fact that this villain appeared in Spider-Man: Homecoming, one assumes was just another of the times Raimi has been needled by the entire experience.
In the end, it seems that Raimi just wasn't happy with the script for the film, and it became clear that the movie wasn't going to make it's panned 2011 release date. When that happened, the decision was made to go into immediate reboot mode.
Unfortunately for Sam Raimi, it seems that Hollywood will not be letting him forget Spider-Man 4 any time soon. At least one more movie is planned under the current Marvel/Sony deal. Tom Holland's Spider-Man will likely continue to be a major part of the future of the Marvel Cinematic Universe. Sequels to Spider-Man: Into the Spider-Verse are almost certainly going to happen. There's also a solid chance we could see Spider-Man, either as Tom Holland or somebody else, in a future Venom sequel. We are going to be getting Spider-Man movies every summer at this rate.