There's a some great pre/post conservation photo in this article: http://blogs.getty.edu/iris/as-layers-of-old-varnish-are-rem...
Digital art does not have this problem.
On a less smug note, truly digital art might not have that problem, but digital representations of analogue art (which the topic of discussion falls under) do. Most movies are just digital encodings of analogue film, and it's only very recently this stopped being true.
And that's not to mention the fact that the way you that you view digital files also affects them. There's the general trend towards denser displays requiring higher resolutions for a file to appear crisp, but even the screen technology itself is a factor - take a look at how much different pixel sprites look on modern displays compared to the CRTs they were designed for:[1][2]
[1] https://twitter.com/crtpixels
[2] https://nerdlypleasures.blogspot.com/2015/03/the-case-for-co...
https://hyperallergic.com/672345/vermeer-restoration-finally...