But this is the point: the AIs will always need input from some source or another. Consider using AI to generate search results. Those will need to be updated with new information and knowledge, because an AI that can only answer questions related to things known before 2023 will very quickly become obsolete. So it must be updated. But AIs do not know what is going on in the world. They have no sensory capacity of their own, and so their inputs require data that is ultimately, at some point in the process, created by a human who does have the sensory capacity to observe what is happening in the world and write it down. And if the AI simply takes that writing without compensating the human, then the human will stop writing, because they will have had to get a different job to buy food, rent, etc.

No amount of "we can train AIs on AI-generated content" is going to fix the fundamental problem that the world is not static and AI's don't have the capacity to observe what is changing. They will always be reliant on humans. Taking human input without paying for it disincentivises humans from producing content, and this will eventually create problems for the AI.