Franchises that manage to maintain high quality usually employ smart strategies, such as selecting talented directors who can provide a fresh approach to the original material. While not every film in the franchise will be a big hit, it is important for each film to respect the mythology that has been built previously and to introduce new elements that can still be appreciated by long-time fans.
Film franchises that can continue to produce high-quality works are usually able to last long due to their commitment to maintaining quality and innovation in each new project. In this regard, they demonstrate that consistency is key to remaining relevant, even if those films do not always achieve massive success at the box office.