It seems to me that digital_media_(artwork), if tagged properly, would exist on over 90% of posts (maybe even 95%). This seems rather superfluous and I can't imagine anyone ever needing to search for the tag.
That being said, I can imagine it being a useful tag to remove from searches to find anything non-digital - however, it's severely undertagged which means it would need a lot of work before this could be possible. This lack of tagging also suggests that most users don't really care about it or even know it exists, which leads me to believe there's little demand for it in the first place.
I'd suggest that only the less common forms of media be tagged rather than the norm, such as pixel art, 3D, traditional, mixed digital/traditional etc. - perhaps a new tag for unconventional media such as papercraft, snow scupltures and food art could be made too. (If such a tag also exists then it should be added to tag_group:art.)
Updated by savageorange