Which is most important in a photograph; composition / aesthetics, technical skill, or the subject / content of the photograph?
For me, it honestly depends. Regarding composition / aesthetics, I would say it is important because you would ideally want to have a photo that shows off beauty, style, and quality imagery, usually in some form of balance or not. One example of this could be a photo that instantly attracts a viewer because it is colorfully flamboyant or all over the place. On technical skill, I feel that this quality is geared more towards aficionados and collectors as they really value fine perfection above many other properties and selling points. But still, technical skill is a must anytime and anywhere and I would be lying if I didn’t say that photos must look picture perfect for presentation purposes or if I was to purchase one for public display.
Lastly, subject / content I feel is always important because it is what sets apart one photo from another, even in cases where photos are similar in concept but different in execution (i.e. a photo of the same person displaying different postures per photo). Ultimately, I think all three aspects of a photograph are super important because with each being given proper attention to from a skilled photographer, the end result would be art created in a true and professional photographic definition.