There's plenty of other art happening, but it's of no real interest to the big dogs - who are far more concerned with ROI than anything else, and consider artistic merit a means to an end rather than an end in itself.
Markets are robust to having very large portions of their demand being transactional, people who are in it to make a profit. But gallerists, curators and agents are overwhelmingly art lovers themselves. No doubt there are plenty of people who are in art to make money but there are many, many more who love art or who are buying art to gain social status (not mutually exclusive motives) than grifters. At the top of any field you’re going to find remarkably few pure grifters. It’s a lot easier to work 60 or 80 hours a week if you like or love your work. Lots of people love art and some of them even make a living at it.
Even with a single Koons piece getting $91M in the secondary market[0][1], the vast majority of actual sales of contemporary art have nothing to do with hedge funds or the Singapore free port. In the art world it's a mistake to only follow the money.
I'm in Berlin right now and some of the most interesting works are not in the super high end galleries but in the smaller ones that sell work in a wide range of prices and actually have to make a lot of sales to stay afloat. For instance my personal favorite Berlin gallery[2] often has works available for under 1000 EUR, and sometimes for more than 60000 EUR for people your grandkids will still find in the History of German Art. That's not atypical.
That said, this article was pretty interesting if very short.
[0]: https://www.bloomberg.com/news/articles/2019-05-16/steel-rab...
[1]: I recently heard Koons described as the "Donald Trump of the Art World," which (fair or not) makes this particular sale a bit ironic.
[2]: https://www.galerie-berlin.de