Hard to say much besides ownership and censorship by capital. But I can give it a shot.

I was listening to this Plastic Pills podcast about the political mythologies of the left vs right, based on the book Mythologies by Barthes. Mythology being an extension of ideology essentially, where symbols that represent ideas in an ideology become entities themselves in a system of symbols to perpetuate the narrative eg. the character of Captain America symbolizes the US but takes on a role within the Marvel mythos which people handle as a symbol in itself, like maybe dressing up as Captain America at a rally

Anyway what they say is, the right has it easy, since all they need to do is continue the narrative or intensify it. But for the left, we are not stuck in some fantasy realm but must live in the material world: we need to actually work to survive before we can start creating political mythology. Also, our goals also lie in the material world -- ultimately revolution can only happen due to material conditions, not people being convinced by a real nice book or movie

There was another interesting point that revolution is the only "anti-myth" ie a myth which actually ends up changing material conditions. I guess they mean The Revolution in the vague sense that leftists refer to, as if it's the eschaton. It does seem mythological, yet if it really does happen, it is entirely material, unlike any other myth. But this also means that everything leading up to the Revolution and everything after it is not part of the anti-myth

I think since this is more postmodernism and post-structuralism, from the French schools, there is a bit of intellectualism about communism here, that leftists aren't being real leftists when "working towards" a revolution or once they took achieve control (eg. the USSR, which they mostly critiqued) they do a revisionism. So take that with a grain of salt

To answer your question, it seems like it's too much work, and it's not really up our alley as materialists. But I still wonder if it's worth it as an artist to make leftist art. Not just a disruptive kind of art that pulls you out of the current capitalist, consumerist worldview that most people seem to bring up for the topic, but a more constructive (?) type of art with grander vision or ability to change and create genres. Something like a Lord of the Rings which birthed fantasy, or maybe reaching further back to religious mythology, since I mentioned the eschaton earlier. I might even ask what a post-Revolution leftist mythology would look like...maybe similar to Soviet Realism?