Akshat K. answered 07/24/24
TA for Linear Algebra Applications with MATLAB/ Software Engineer - AI
The "they say" claim is basically what viewpoints, opinions, whatnot the author uses to set up the argument. What other people say about the topic at hand, which sets up something for the author to agree or disagree with. For this article it's what "they say" about american food, like people assuming everyone eats hamburgers for example.