"An idea has no worth at all without believable characters to implement it; a plot without characters is like a tennis court without players. Daffy Duck is to a Buck Rogers story what John McEnroe was to tennis. Personality. That is the key, the drum, the fife. Forget the plot."
People in the world
you are looking to for entertainment.
Basically one of the most super of tropes
in all of fiction. Unless you're writing some sort of abstract poem, it's pretty much impossible to tell a story without characters
, Characterization Tropes
, Characters and Casting
, Characters as Device