Some things need funding despite being unprofitable. Not everyone will agree, but I believe art/culture (including often unprofitable forms thereof) are worthwhile, and should thus receive public funding (to some degree). I believe the same about justice, policing, education, research etc.
None of this rules allowing a freeish market to operate where doing so "delivers the goods".
You have to make an argument on _why_ market forces don't compensate artists fairly. The standard argument is that art is a public good with a free rider problem– a mural might produce value to everyone who looks at it but there is no way to force them to pay for it. That argument fails for many of the things this program is funding: theater, opera and film. All examples of art that is easily excludable.
i do not feel that we have a shortage of art and in fact we have much more art than in past years where everyone was forced to do agricultural labor.
art is relatively low on my list of positive externality activities to subsidize, after stuff like ensuring everyone has food to eat, home, etc. at least in the US, we are already running a deficit so we do not even have the money to do this - let alone some broad UBI for artists.
and how do we agree on what jobs are undercompensated? every person will have their own hobbyhorse
Yes, if we are worried about the amount of art we have available then maybe we should focus on making existing art available first (e.g by reforming copyright) instead of wasting money on dubious programs to create more of art that will be locked away.
food commodity trading? idk sounds speculative and ignoble to me, probably don’t need it - more money for the artists!