a truly spectacular composition, a stellar one, of a truly boring subject, is still a boring photograph,
the composition doesn't help detract the viewer from the fact that the photograph is not good.
there are millions of poorly composed good photographs, and millions more to be taken
but the subject matter usually over-rides the poor composition.
i don't think there is any one or 2 or three or ? things that are most important ... maybe just one
"being there" mentally, spiritually and physically, unless you are ted serios, then you don't even have to be there.