Actually while Bakshi was the first to make a movie that went all in on rotoscoping (particularly Fire and Ice where it was 100% rotoscoped while LOTR was a mix

Actually while Bakshi was the first to make a movie that went all in on rotoscoping (particularly Fire and Ice where it was 100% rotoscoped while LOTR was a mixed bag) the first animated film to heavily leverage rotoscoping was Snow White.