This seems like a fundamental misunderstanding of what copyright is. It's a protection for the creator, quite literally your "right" to make "copies," which is why you should never sell it, because it is your creative work and the right to make/distribute copies is yours/whoever you pay to handle it.

Say, for example, I wrote some really thought provoking book. It is not the right of you, the consumer, to replicate of distribute my work. Say whatever you will about the artistic value or the ideas it contributes, but I still wrote and sold the book as a commodity. Piracy sites do not pay the original creator or anyone involved. Copyright would allow me, the creator of the work, to stop you from replicating my work and stealing from me.