>My sense is that this, along with a lot of other writing decisions in shows like The Simpsons, is a form of “cashing in” on the investment of developing a character.
I wouldn't even quote cashing in, the effect is just an artifact of chasing demand signal to improve revenue. It's the same as iterative agile development that chases short term demand signals and over time tries to optimize the aspects that bring in money. The underlying driver for all these effects is capitalism.
You see characters take on bigger or smaller roles over time depending on audience response often. Jar Jar was cut back drastically Star Wars 2 and 3 compared to 1. Some characters even get spin off shows, like Young Sheldon from Big Bang Theory.
I wouldn't even quote cashing in, the effect is just an artifact of chasing demand signal to improve revenue. It's the same as iterative agile development that chases short term demand signals and over time tries to optimize the aspects that bring in money. The underlying driver for all these effects is capitalism.
You see characters take on bigger or smaller roles over time depending on audience response often. Jar Jar was cut back drastically Star Wars 2 and 3 compared to 1. Some characters even get spin off shows, like Young Sheldon from Big Bang Theory.