It seems to me that content will get created regardless. Whether it's better is as you say a matter of taste, but both worlds have existed.
You can't be serious that Avengers is on par with the epics.
> How many patrons will pay to have something made in the current world, knowing they could just recoup their money?
How could they recoup their money, if there's no exclusivity? There's nothing to sell.
> It seems to me that content will get created regardless.
I guess ultimately, there is absolutely nothing stopping people in today's from creating the best content they possibly could, except for having to cover their cost of living. Today's IP protections allow them to cover their cost of living by creating content. A lack of IP protections means that creation will always be a second or lower priority to a vast majority of creators (those not sponsored by a patron)
To me, that means that a world that lets them create as a method of covering their cost of living is a better world for those creators.
A patron, in comparison, is a single entity who is interested in the book, and who is capable of shelling out the $50,000 (a nice round number representing the salary for a good, but not great, writer and editor for the duration of getting the book produced) to have that book made. I'm not capable of doing that; I am guessing most people are not.
> it bears consideration whether the corporations who make things for profit are as good at creating such works
That's up to each person to decide. Is GRRM's Game of Thrones such a work? The Dark Tower series? Avengers Infinity War and Endgame?
Honestly, I think that yes, in many ways they are on par with or superior to books such as the Illiad and the Odyssey. They are absolutely better than Moby Dick.