Interesting. I did this google search and i get this:

"Yes, coffee is predominantly water , with a standard cup of brewed coffee being about 98% water and the remaining 1-2% being solids like caffeine and antioxidants. Because water forms the vast majority of coffee, its quality is crucial for a good cup and it contributes to your daily fluid intake"

Yeah, it was just a creative example of the type of awful AI responses search engines, including Google, give. It tends to contradict what you say, push everything towards useless and inoffensive "there are many complicated factors" analysis, and even contradict itself.