In Miyazaki Hayao's The Witch, the black cat finally didn't speak. Why?

It turns out that Ji Ji speaks by the magic of Kiki. In the middle, she found that Jiji couldn't talk, and then she flew around, indicating that magic was weak, so Jiji certainly couldn't talk. Later, I still won't, because I fell in love with cats, often stayed with them, and got used to using cat language. Later, Kiki grew up and stopped talking when she no longer needed Kiki.