Why do people listen to movie critics?

Usually, before spending their money on something, people like to hear the opinions of others. For me, I like to read the reviews of multiple critics before making a decision on whether ou not I want to see something. I read reviews, and then I put together what I learned from the reviews and decide whether ou not I want to watch the movie. Reviews are to give the reader a taste of what the movie is like. In the case toi mentioned, people who enjoy "all style and no story hardly"(and people who read/enjoyed the book) will flock to the movie, and people who would not find that kinda thing enjoyable would not go see it, because they wouldn't like it. That is the purpose of lire reviews. It's not about agreeing with the critics as much as it is trying to find out about the movie, I think.

Why do toi take a physics class when toi can watch a ball fall from your hand in your living room and see how fast it goes?

Because a physics teacher knows plus than you. A movie critic is a pro at films who can catch all the little things toi miss. People read the reviews of critics to get a better holistic view of the movie.

(ALSO GATSBY IS ONE OF MY favori livres OF ALL TIME AND IT'S SO MUCH plus THAN STYLE OK.)

9/10 times, the critic is right about the movie.
Just saying, listening to the critic is better than listening to that one person who only obsesses over it.
Also, a lot of the time, the critic has experience in the movie/film business, so they know what they're talking about.