Snow White is absolutely early animation. It's the first ever American animated feature film ever released, just like Toy Story was with CGI. It's also the first non-lost "traditionally animated" feature film, in that it didn't use cut out or silhouette or stop motion or hybrid. Even if you compare Toy Story to the first feature films (that still exist), such as The Adventures of Prince Achmed or The Tale of the Fox, they still look better than Toy Story.
And if you want to use Gertie the Dinosaur or Little Nemo, or other Winsor McCay stuff (or even older Disney stuff, ala Merry Melodies) you're going to have to use older CGI works as well. I'm talking Money For Nothing, and '93 Veggie Tales and projects like that. In that case, traditional animation still holds up better.
And as far as something like Up and other Disney/Pixar stuff holding up 20 years from now, we'll see. CG stuff has a tendency to age relatively quickly to what we would expect, as we've seen from tons of CG films and video games in the past. It's not a mark against CG or anything. It's more because CG already tries to look closer to reality than traditional animation, so it gets stuck in a very unfortunate uncanny valley situation. People are less likely to closely observe 2D stuff, and so it naturally holds up better.