A couple of years ago I saw some of Steve McCurry's work in a gallery. Most of the images were 16x20 format or thereabouts. Having never seen any of his work in person aside from the famous magazine covers and on a computer screen, I was expecting to be impressed. Up close, most of the images just fell apart, some were quite grainy, I assume having been push-developed. Others weren't quite in focus where they should be, or had visible camera shake. And yet, a step back, at proper viewing distance, with my nose out of the pixels, they were clearly good photographs. His skills as a photographer were evident, the scenes were well-envisioned, the humanity of the participants was on display and I felt drawn in.
Talent matters, and moreso the skills and the years of striving that round it out. I get tired of all the breath wasted on trying to quantify image quality as if it were an intrinsic property of the medium and tools of photography. Shakespeare in a tattered, moldy old paperback will always contain Shakespeare's genius, and is not diminished by the presentation. In the discussion of Edward Weston's darkroom the other day, much was said on the subject of its simplicity, of the sparseness of his darkroom, and the basic nature of the tools he used. His vision as an artist was the deciding factor and he molded his tools to accomodate that vision to the best of his means.
We discuss the quantifiable aspects of image making because they are seem objective, repeatable, and expressible. The technical aspects are necessary but not sufficient for photography, as an art. Will future photographers look at today's digital work in astonishment that today's photographers only had 16 or 25 or 50 megapixels to work with? Or is this era one where technical limitations were virtually stripped away, leaving only each photographer's ability to see as a distinguishing factor?
I would never argue that the latest generation of phone cameras, or digital cameras in general, offer everything than a film-based process does, but any camera ever made has been sufficient to make photographs with and that remains the case, iPhone 6 included (and aside from Apple's marketing the device as something special).
Image quality lies in the cultural sphere, between human beings, in the minds, perceptions, etc, not in a camera, in a negative, not in the transformative power of light on silver halid crystals or on the tabula rasa of a CCD.