It influences a lot because, as the story is evolving so is the setting.
It matters because, without setting there's no story.
I believe that setting is the most important part of a story because, it tells u many things..
For Example :
TIME /PLACE /BACKGROUND OF STORY /AND WHERE SOMETHING TAKES PLACE..
in the house, park, pools, hotels, movies, Etc....
Use care with secondary clauses. Use active voice. Use powerful verbs. Follow grammar rules