I was asked this question by a friend about a year ago and it occurred to me again the other day while painting with watercolour after much time using only pen and digital brushes. The question then took me by surprise but after a short consideration I answered; “the amount of time it takes to create it..”.
Of course this isn’t the only factor but I still think my fast response is accurate. As much as I think that digital art is not inferior to traditional techniques, the same way as washing machines are not inferior to washing by hand, it’s still not on the ” same level”. It’s no doubt easier and often faster to paint with digital brushes with results that often make reality blush, but a) where’s the wonder, b) the time it takes until the end result is much shorter, thus eliminating a great chunk of personal connectedness to the artwork itself. When it took painters years to finish a serious painting, their relationship to it and their approach to the creative process was much more personal.
This personal and often times emotional approach is what, in my opinion, digital painting (mostly) lacks and when it comes to art, which is always subjective, this alone can make a huge difference. Ready-made and copy-paste art can be useful and even appealing but is it “good” art? (“Good” not in the sense of quality but in the sense of being the product of a skilled artist thus being of a higher value.)
Some even argue that artworks created with digital techniques cannot be called art at all but I consider it a very one-sided attitude. Following this argument, only the cave paintings would be “original” and “traditional” enough to be called art.
Of course this debate has many more angles but I think at the end of the day what matters is the artist’s relationship to the creative process itself and how much skill the artwork reveals. Also nowadays the fusion of many techniques makes the whole debate somewhat barren.