The biggest factor was (Elena Gilbert) leaving the show after Season 6. The writers carried on for Season 7 without her, focusing on the Salvatore brothers and the supporting cast. However, by the end of Season 8, the story had naturally run its course.
The answer is simple:
If you’ve just stumbled into the supernatural town of Mystic Falls—or you’re considering a re-watch—one of the first questions you probably have is: How many seasons are in The Vampire Diaries (TVD)? how many seasons are in tvd