> I don't see why you need to restrict it to actual photos of actual things.

We don't need to, although in that case, we might think of what we are doing as digital painting rather than photography.

> some sense of legitimacy as being "real"

A photograph is a purely-2d purely-visual representation of what we inescapably experience as 3d and multi-sensory. It can be "a real photograph" but not "real".

If what we are interested in is a documentary representation then we are making some additional claims about how the "real photograph" was made.

> any emotion by cherry-picking from a huge set of shots

Once upon a time, in the age of film photography, photo-journalists did take a huge number of exposures and have someone else process the films, and then select particular frames from contact sheets. Digital reduces that cost.

However, when someone looks at a photograph, they bring all of themselves and a little of the photograph.