Unlike The Simpsons Movie, The Bob’s Burgers Movie found time to utilize the show’s expansive cast in its brief runtime. Both The Bob’s Burgers Movie and The Simpsons Movie have relatively brief runtimes compared to many modern theatrical releases. The Bob’s Burgers Movie runs 1 hour 42 minutes while The Simpsons Movie runs 1 hour 27 minutes, meaning neither had time to throw in an appearance from every cast member of their respective shows.
However, from South Park to The Simpsons, every animated show which creates a theatrical spinoff faces this issue. Some characters just don't make the cut thanks to the compressed runtime of movies and the prohibitive cost of animation, meaning screenwriters and directors have to be judicious in which characters they add to the story. However, The Bob’s Burgers Movie pulled this off far better than The Simpsons Movie by avoiding one major screenwriting pitfall.
Even though The Bob’s Burgers Movie arrived 12 seasons into the show’s existence, it did an impressive job of giving cameo appearances to most of the show’s large cast of characters. The spinoff managed this because the film didn't introduce many new faces. The Simpsons Movie, unlike The Bob’s Burgers Movie, earned fair criticism for taking screen time that could have been given to existing favorites and instead gave it to characters like President Schwarzenegger—who really should have been President Wolfcastle—and Russ Cargill, who was barely different from the show's earlier beloved one-off villain Hank Scorpio. Even though The Simpsons provided its movie spinoff with thousands of characters to bring back, The Simpsons Movie still made the odd choice to add even more one-off characters to the show’s ever-growing roster.
This resulted in The Simpsons Movie taking time to establish new characters, thus leaving little screen time for appearances from old favorites. While the sheer size of The Simpsons cast means no one could argue that the likes of the Honorable Avril Ward and Chester Lampwick needed cameos in the spinoff, the film adding new cast members worked against the movie. For example, Lisa’s love interest in The Simpsons Movie was a new character who viewers had never seen before, meaning her subplot with the character was a lot less effective than Tina’s pining for Jimmy Jr in The Bob’s Burgers Movie, a long-established storyline with pre-existing stakes.
While The Simpsons Movie’s new characters did provide some classic moments (such as Russ Cargill’s unhinged search for the titular family), by and large, they were unnecessary additions who filled roles that the existing supporting cast of The Simpsons could have taken. While not enough to derail the movie, this decision did make The Simpsons Movie feel less like a culmination of the show’s work up until that point. In contrast, by including a range of characters from throughout the show’s long history, The Bob’s Burgers Movie managed to make its theatrical spinoff into a victory lap for the successful series, where The Simpsons Movie was more of a standalone adventure.