No offense, but it's an article in the New Yorker about an issue in California. Your comment makes about as much sense as if you had said "yeah but you need to

No offense, but it's an article in the New Yorker about an issue in California. Your comment makes about as much sense as if you had said "yeah but you need to know that California is a state in the US". Europeans might not know it, but the target audience of the article certainly does. It's not exactly an extra bit of knowledge you need to learn, it's something you already know.