Once upon a time, Sheet Music Publishing was the domain of engravers and inverse copper plate, with ink, paper and guillotines galore, The advances in publishing technology that routed type-setters in the 1980's has left Music Publishing in a strange place. Record deals that once were so lucrative for a 'Band' are no longer doled out like Polo-mints after a Curry night out with the A & R man. CD duplication is waning, and now High quality $0.01 cents per click Streaming have put paid to that gravy train.
Publishing deals for contemporary composers were a huge risk investment for music publishers, 'back in the day'. How then to monetise a compostion that might only attract a few hundred sales if that? What hope is there then for the aspiring composer? Moreover, why would anyone wish to listen to your music unless you had invested heaviliy with an unshakeable self-belief, a mission to be heard and performed. There is alway a niche market for some kinds of music or work, or audio recordings; you just have to 'keep at it' so they say.
My own 'music catalogue' of works spans more than 40 years now and I have no idea how so much time has dashed by so quickly, nor how it happens to be, that I still don't have a complete publish-ready set of copies of my musical composition works to sell 'online'.
Let's just say that it's a work in progress, taking as much care over proof-reading and type-setting, music engraving that would have been someone else's full time job less than 50 years ago. It ain't easy!