Here's why Full House didn't get a ninth season. Debuting in 1987, the ABC sitcom introduced fans to the Tanner family based in San Francisco. The show's events were kicked off with the death of Danny Tanner's (Bob Saget) wife, leaving him to care for his three young daughters — DJ (Candace Cameron-Bure), Stephanie (Jodie Sweetin), and Michelle (Mary-Kate and Ashley Olsen). The patriarch gets some help from his brother-in-law, Jesse (John Stamos), and best friend, Joey (Dave Coulier) who move in with them.
Over the years, Full House saw the Tanner family grow older and bigger. Jesse eventually married Rebecca (Lori Loughlin) and got kids of his own in twins, Nicky and Alex. Meanwhile, Danny's girls went through various experiences — DJ started dating Steve (Scott Weinger); Stephanie learned to not succumb to the peer pressure, and Michelle, despite being the youngest, became a guiding figure for her cousins. While Danny and Joey stayed relatively the same, they also went through respective experiences that made them become better parental figures to the kids in the house.
Known for its ability to subtly incorporate delicate subjects into their narratives, Full House was both a hit to parents and younger viewers. It amassed a loyal following that proved to still be invested in the Tanners decades later as proven by Netflix's Fuller House. The spin-off sequel ran for five seasons and put the focus on DJ, Stephanie, and their long-time friend, Kimmy (Andrea Barber). With an established fan community that stuck with it until it was recently revived, it's curious why Full House ended with only eight seasons in the first place.
There were a couple of reasons why the family-oriented sitcom didn't get a ninth season. By the early '90s, viewers were starting to lose interest in family shows; the focus shifted on sitcoms featuring an older cast instead, with sitcoms like Friends, Seinfeld, and Frasier. Because of this, ABC decided to pull the plug on Full House, with season 9 being its last. It also didn't help that at this point in terms of the show's narrative that the Tanner girls were outgrowing the show's initial premise. DJ was basically a young adult who was off to college and whatever the show could do with Stephanie and Michelle in terms of parenting storylines, they already did with their eldest sister.
While Full House brought in two new baby boys in Jesse's twin sons, they're just not as focused on unlike their cousins, particularly Michelle. ABC may have dropped Full House, but the show could've continued over at The WB (now rebranded as the CW) after the then-budding channel tried to pick it up for season 9. However, some of the cast members were already gearing up to move on from the sitcom. Cameron-Bure and Stamos in particular refused and considering how pivotal DJ and Jesse were in Full House, it would have been very difficult to move forward with the series without either of them.
In hindsight, it was time for Full House to end when it did. The storylines started to become less interesting and even ridiculous with the final arc having Michelle suffer temporary amnesia. It was for the best that they walked away from it knowing that it's had its run rather than forcing it to continue by overstretching its plot.