The squeeze is going to come simply because at some point there is far more content than buyers.
Lolz. I'm sure you wouldn't mind using pictures of mulleted '80s dude in your advertising. And in 20 years, all these bearded gentlemen being photographed today will look so silly. Fancy a NY skyline with a couple of extra towers?
The problems with professional photography have nothing to do with durability and everything to do with technological advance in the overall process. The easier it gets to take good pics and tout them to the whole world, the more competition there is, the lower prices are inevitably going to get.
Photographers are like recording musicians, their bread is becoming tied to real-life presence - something that remains unique and effectively not scalable.
So no, there always will be something to be photographed.
Add in that an image competes globally and is infinitely scalable and that is essentially perfect competition with the prices to match.