If you are talking of the quality of the animation itself, and not just the storytelling that would be lacking, then you also have to factor in Kodak.
Starting with 101 Dalmatians, Disney used a new Kodak developed drawing process which was a marriage of painting and photography. The process's name escapes me now, but it goes like this... Before, Animators drew, painted and inked every frame in a film, which is why Lady and the Tramp and Bambi were so pastoral and beautiful in their look. They were also very expensive to make. Disney wanted a cheaper way to make animated films. 101 Dalmatians used a new photographic process, that made the resulting prints less refined, and lacked color and warmth, which is fine for a stark film as that, but for The Rescuers, Aristocats, Fox and Hound, etc, there was something lacking in the look of the animated features of the 60s and 70s. They were going to shut the animation dept. down after the dismal returns of The Black Cauldron, when Jeffrey Katzenberg took over and resurrected the dept. The late 80s and 90s used computers to eliminate that photo "thistle" look of the process, which started with Oliver and Company and improved in Little Mermaid. The Lion King got the computers right though.
Examples...Look at the sharpness and fit of the lines, also the colors from Sleeping Beauty...
Now look at the jagged edges that this photo process has done to the Aristocats. Notice that all the outlines are black, and not a supportive color as in SB?