But the tech stack is much deeper than derivative works ever could be. Some derivate three generations down from Donald Duck is probably no longer a derivative

But the tech stack is much deeper than derivative works ever could be. Some derivate three generations down from Donald Duck is probably no longer a derivative of it, judged by current standards. But the computer I'm using right now could reasonably be covered by tens of thousands of patents all the way back to the origins of metallurgy, if those didn't expire.