There's a world of difference between a smartphone snapped photo by a volunteer and what a professional photographer would produce. The first will give you a pretty good idea of what's going on, but will be completely unsuitable for what's effectively a display ad.
For instance in the charity I run, we have about a thousand pictures of real operations taken by amateurs. For our posters we still prefer staged professional photos, since they look 100x better and communicate our message much more effectively. And yes, it does annoy me that this is the case, but again, the goal of my charity isn't to pursue truth in advertising, it's to achieve an actual goal (which is the goal people have already entrusted us with their real money, so one does have a healthy fear of wasting it).
On a deeper level it's sort of like why paintings sometimes feel more true than photographs in the sense that they can communicate how we perceive a place and what it means to us in a way that a photo often cannot.