The artist's path is often rocky, filled with traps and wrong turns. If we spend out time envious of other artists - jealous even - then our eyes are not on our unique path. The result is that we can stumble and fall. Perhaps lose our way completely.
Every artist can learn from other masters, but that is a whole other thing. Learning is positive. Envy is a negative emotion that keeps us down. Be free of these thoughts and free your art.