As to dematerialization, yes, the traditional art object has become less interesting to the vast majority of viewers over the last 30 years. It is harder for artists to sell and exhibit traditional artworks as they are becoming more out of touch with contemporary culture. I don't know. We're now in the riptide of a much accelerated process where markets and media converge. Everything is virtual.
Reality is true.
But here catagories can start to slip again. The fewer expectations the better. I try to withhold my preconceptions. For example, it did not surprise me at all to see a telepresent bowling alley at the Walker. These are all just symbolic interactions that exist through social constructs.