If I steal something from you I have it and you don’t. When I copy an idea from you, you still have the idea. As a whole the two person system has more knowledge. While actual theft is zero sum. Downloading a car and stealing a car are not the same thing.

And don’t even try the awarding artists and inventor argument. Companies that fund R&D get tax breaks for it, so they already get money. An artists are rarely compensated appropriately.