I do think that photography is shrinking away. I have no figures by which to back that up, other than the numbers thrown around for camera sales.
However, it strikes me that it was always an older generation thing; even when I was a teen back on the 50s, it was a bit of a lonely interest. For sure, nobody else I knew in school was interested in it. There's no doubt that only having the blessing/curse of a so-called artistic nature made me interested; it was key to a world of glamorous girls and making pictures of them. Without that combination of art and sex apoeal, I can't imagine anything else that would have made me want to own a camera other than, perhaps, music photography and movie stars, but hey, at best, that's taking us straight back to art.
Only later did I pick up on the art of people like Leiter and his way of seeing the physical world around him; before him, it was all fashion magazines and similarly impossible ambitions. Now most folks don't give a monkey's about that stuff, so what is there that the cellphone can't cut just as well?
As Nick Knight says in interviews, holding up his iPhone, photography is the past. Imaging is the present, and that is a combination of many disciplines such as design, graphics, motion and sound. In one interview he challenges the host about why she teaches analogue in her college as it has no more relevance for anyone seeking employment in the new mixed medium that has replaced what was known as photography.
In one of his last interviews, the late Peter Lindbergh holds out little hope for future photographers either, but more from the point of view that who wants to work in an environment where twenty people huddle around a monitor and interrupt the poor old photographer after every click? That kills the development of chemistry between photographer and model, and leads to the design of camels.
So yeah, not only a mature market, but a dying one.
Rob