"Art is not to say Aesthetics." This is true of contemporary art.
However while the Sistine paintings may well be considered a creation of genius on Michelangelo's part even to contemporary Art critics, Aesthetics WAS the ultimate reason for its being created in the first place.
The church's relation with Art was historically one of functionality...their aim was to get across fundamental concepts of awe inspiring greatness, through image storytelling. It was a commission, a paid job, not an act of self-gratification that then hopes to find post-resonance with a viewing public.
While contemporary Artists create according to a unique inner calling, one that should ideally be without monetary influence , this was not the case for past Artists who all worked on payment, nor was this the reason the Sistine works came to be...in fact in this specific instance, worse still, Michelangelo had been asked against his personal preference of sculpting, to paint.
The point being that while the subject of Art as a modern philosophy has been given much attention, Aesthetics was left on the freeway without a driver. We still provide Aesthetics but it is often as slave to ideological concepts that belong to Art or are left as a vague notion that says beauty is in the eye of the beholder: so just DIY it.