Backstory is a design tool, just like character preparation for an actor. It makes for a rich believable performance, but, like character prep…it’s for the artist. The audience sees the result. Folks love Venice, Italy. Almost no one knows the backstory of how it got that way.
I have asked something like this with people, where can there be too much theming/backstory?
As @robjyeo said to me, does a popcorn cart need a huge backstory of the owner of the stand's great great great grandfather found a mystical city of corn?