Are we running out of new music/​movies/​art from a metaphysical perspective?

It is difficult to judge at first, but it appears that some music genres (classical and jazz especially) have seen a radically slowed or non-existent output of significant works in recent decades. By significant, I mean works that would be seen in league with the most acclaimed artists in the genre (eg Beethoven, John Coltrane). In a similar way, there is a building popular consensus that Hollywood is not pursuing original ideas as much anymore and is relying on rebooting old stories and franchises. But is this because of a fault of the Hollywood system, or is it because there are few significant movie story ideas left that have not been done?
It seems to me that there are limited possibilities in art (or any field) of what we can discover or create. It appears that the matter and rules of the universe (in concert with human nature) manifests itself into these limited possibilities. When we develop a field or genre, we learn and create at an increasing rate but then eventually “complete” the field (in a boom and bust pattern).
I wrote a brief article called The Big Niche to try and explain this concept.
The relevant questions seem to be:
  1. Do you agree that from experience and observation, we can tell that certain genres or fields appear to become completed?

  2. Does this concept or another concept best explain what is happening?

I’m interested if any of you agree with this line of thinking or have other possible explanations of this phenomena.