The days of the trade show are numbered, sadly.
I go to a big building industry fair in Bologna nearly every year. One it took a whole day to visit just the sectors that where of interest, including some eye candy in the site equipment zone.
The last time I went it was a quarter of the size of the exhibition that was held ten years ago. I spent a morning seeing the things that interested me.
So I suppose, Photokina has just followed this downward trajectory.
We can get almost all the information from the internet now, but there is nothing like holding a piece of gear and having it explained by a good demonstrator. I do not see this decline of the trade show as something positive.