I think you are right, AI content will not be distinguishable from human content. What we really need to figure out is the direction that we are going as humanity. This planet must quickly become too small for us, human beings will not be needed anymore which means we need to find bigger challenges or we will self destruct out of pure laziness and self indulgence. Personally I don't think AI will only destroy creative and cognitive sectors, it will destroy absolutely every single sector in existence. There won't be a single job left that a human can do better than a robot. And humans will also pick the robot worker over the human worker every time. This is what happened during the industrialization, it's not like a few factories said: "hey you know what guys, let's be a bit quirky and still use 100% humans for this factory just because we can.". No, nobody is going the human route. It would be objectively slower and worse and therefore you go with the robot. There isn't a single area in life where you wouldn't pick the robot over the human and the question is solely how fast we can get to implant some good AI into mechanical bodies.