Both franchises have similarly respectable roots but both veer off in the end.
‘Saw’s’ concept was born from the creators, James Wan and Leigh Whannell, wanting to make a movie but having less than 1 million dollars to do so. Their predicament led them to come up with the idea to set most of the movie in 1 room. Cary Elwes (Dr. Gordon) explained how Wan and Whannell expanded on this idea for the rest of the movie’s story (0:33).
The whole concept of the film was born out of the fact that they had no money. We can’t have them leave the room, so we have to chain them somehow to the wall, and then they asked themselves the question, “why are they changed there?”
‘Paranormal Activity’ was also made on a low budget, but this was done on purpose to show how effective smaller budget horror movies can still be, which ‘Saw’ reminded people of. The first ‘Saw’ was a huge hit popularizing the horror sub-genre preferred to as “torture-porn,” as ‘Paranormal Activity’ did with found footage, for the modern generation. Given ‘Paranormal Activity’s’ link to the franchise, Wan and Whannell’s inspiration for ‘Saw’ ironically came from ‘The Blair Witch Project.’
Whannell served as a writer for ‘Saw II and Saw III’, and him and Wan worked on the story together for ‘Saw III.’ For them the story ended there, but Twisted Pictures, production company, decided the hell with artistic integrity. The franchise was continued for 4 films, with a new film continuing to be released every October.
Like with every genre and sub-genre, audiences grew tired of torture and turned their attention to found footage, when ‘Paranormal Activity’ beat Saw VI in Saw VI’s opening weekend at the box office. This proved that the ‘Saw’ Franchise, for a way of speaking, became a cow that couldn’t milked much further, which resulted in Saw 3D being the end of the franchise.
With that, ‘Paranormal Activity’ became the new ‘Saw,’ and new installments would be released every October for the next 3 years. Paranormal Activity lost momentum way quicker than Saw though, as audiences decided to tune after the 4th one was just the same thing again. I honestly keep forgetting ‘Paranormal Activity: The Marked Ones’ exists, and hardly anyone even cared about 2015’s ‘Paranormal Activity: The Ghost Dimension’, which proved to be an unsatisfying conclusion to the series.
If ‘Paranormal Activity’ had ended after the first film, the movie would be held in much higher regard. Sure, a lot of people think it’s great, but the movie’s reputation was retroactively damaged by how worthless the sequels were. Saw, at least, kept its dedicated fan-base to the end, even though they were just taking advantage of them. The ‘Saw’ and ‘Paranormal Activity’ franchises are similar to how the ‘Twilight’ and ‘The Hunger Games’ franchises ended up going. Despite the unnecessary splitting of Breaking Dawn for two movies, the fans were still invested. By the time, Hunger Games did the same thing, the final film’s returns weren’t as great as they could’ve been, if the final book was just made it one movie.
As for the future of the ‘Saw’ and ‘Paranormal Activity’ franchises, Saw seems like it’ll do better, commercially, in the end, as an 8th film is on the way. There’s still interest in the franchise, where Paranormal Activity pretty much became a dead horse. While there aren’t any future installments currently planned, there is a VR game coming out this year. Unfortunately though, both these franchises should’ve just stopped while they were ahead, as it is with most movie franchises.