OverAnalysis-chan to the (unnecessary) rescue! 😊
It's a word association thing. When most people hear the word "cartoon" they think of movies and shows for kids (Looney Tunes and Disney and the like), and normies tend to call anime "kiddie stuff", so separating "anime" from "cartoons" is their way of saying that anime isn't just kids stuff. Hence the start of this whole debate.
That said, it really doesn't matter what you call anime except "amazing" ❤❤❤❤❤