I think one of the main problems with cardistry as a performance art is that it's difficult to express meaning. For example, your performance would struggle to be a narrative, due to a lack of character, for a start.. It is obviously hard to give the cards a character, due to a lack of distinguishing features identifying each one. Nobody is going to be looking out for our hero, the eight of clubs; that would be ridiculous. However this isn't an unsolvable issue by any means. Why not simply have multiple people collaborating on a cardistry show? Whilst it is by no means unheard of to do a solo performance, it is much more common to have theatre and dance performed by a group. Picture, for example, a small child sat with a tatty old deck of grubby cards, slowly and jerkily doing a three packet cut, when all of a sudden a smart man with perfect posture strides past doing a huge packet display with a pristine deck of smoke and mirrors. Just from that, I expect you could start telling me about these people. Furthermore, you have the basis for a narrative, which would be otherwise impossible to do with cards. Now this may not be what everyone had in mind, but you can certainly see how it is taking cardistry and starting to build something that may be seen as art out of it.
Just another issue I see is that of size. If, for example, a dancer wanted to portray a huge monster, for lack of a better example, they could spread their arms wide and stretch every inch of their body to give an idea of size. This is much harder with cardistry, as you are limited by how many packets you can hold or whatever, but again, not an unsolvable issue. Just one possible solution would be using multiple people as one person or object. Here I reference you to the dance 'Bird Song' by Siobhan Davies, most notably the section entitled 'Snake 1' (I'm having difficulty finding a video, but if I do I'll update this post). In this, a group of eight dancers work together to give the impression of one long snake. Why could the same ideas not apply to cardistry?
I feel that, at the moment, it is not an art, nor is that looking like changing. However, as I hope I have shown with this brief medley of ideas, which I am quite literally making up as I go along, it has the potential to be something more, should people choose to take it in that direction. I can't foresee anybody choosing to do this in the near future, but it could theoretically happen. What I've typed here is coming from the point of view of an actor and dancer, so I'm going to see it in a different way to some other people, but even if you don't like the ideas given here, I hope you can see that it has more potential than people are giving it as an art.
Incidentally, I may have just become the first person to ever offer suggestions for giving cardistry character