In this specific case we are talking about, an image marketplace, there is no law that requires the marketplace to have KYC.
But if there are copyright issues and there is no KYC, it is the platform that is sued and not the person who actually violated those rights.
I think any operator of No-KYC marketplace knows that if he operate it openly, not hiding his real ID from the state, he will be arrested very quickly, e.g. for assisting to launder crypto from drugs sale.
Copyright law is your least concern when you assist a rebel group, which is hostile to the US govt like Houthis from Yemen, to buy parts for making suicide drones.
So "No-KYC" in real life means "will NOT cooperate with the state in any case".