All art is nothing more then a quest to achieve absolute truth. The very few who are successful in this goal make all other efforts essentially redundant. There is no fiercer competition.
I think the that competition to pigeon-hole the multifaceted contributions of complex, gifted, and often often inconsistent artists into a simplistic, pass-fail , binary model is a pretty fierce competition as well.
It is my personal opinion is that we lose a lot or our understanding of great artists by bleaching them of their humanness and oversimplifying how we view them, forcing them to conform to standards we define long after they are dead. I've made this point in other threads, but I personally find it hysterical how we mythologize the creative processes of Shakespeare and Dickens (both of whom I adore), while both were essentially hacks, cranking out materials to support an immediate audience. Was the stage direction "Exit, pursued by Bear" from the Winter's Tale a lasting insight into the relationship between man, nature, and fate? Or was it a quick hack to remove a character that was no longer needed? IMO, it is their empathy with the human condition that made Dickens and Shakespeare so successful, and made the initially transitory nature of their art into something of lasting value.
Likewise, I adore Bach. (And yes, will gladly call him a genius). But do we owe the huge amount of cantatas he wrote to a sublime search for absolute truth, or the fact he needed music for performing each Sunday? Did he sit down each day to make a lasting monument to civilization, or to write something for someone to play? Let us hope for Bach's sake that he never prostituted his need to capture ABSOLUTE TRUTH by writing exercises for music pupils to play. If he did, I'd guess that we would need to pull him off the pedestal. (Oops... he did, didn't he? Too bad. I liked him. )
One of the themes that shows up a lot in the fiction by Vladimir Nabokov (and, unfortunately, in too many of the Biographies I've read) is that the biographer takes over the story, uses it to address some personal agenda and the purported "subject" of the biography becomes an afterthought. I've always found this approach to be quite onanistic, and lacking in respect that the artist deserves.
Of course, this is all my silly opinion-- I don't want to conflate it to anything more than that. In my own personal musical hierarchy, I wouldn't put Liszt or Wagner in my "genius" category, just in the "awfully damn good" category, but that is just based on my personal reaction to what my ears tell me. And if someone wants to tell me that I'm lacking in musical taste, they are probably right....