Policing this stuff will not be fun.
During some of my most active posting periods in the past few years I was a few times accused of being a bot. Why? I type fast, and I responded and wrote lengthy articles very quickly. I was producing a lot of content.
I've never used a bot or AI to generate my content.
Why do I mention this? If I ever do get the desire to be that prolific again I think there is a chance I might be falsely identified as being AI. This is the risk of trying to stop bots. People get falsely flagged.
It is going to become increasingly difficult to detect actual AI content. If we do flag things based upon patterns the people authoring the AI will read that criteria and alter their AI. At some point AI will be able to thread that needle while ACTUAL people will likely frequently be falsely called AI.
You make some rather valid points, I think as AI learning becomes more accomplished it will become more and more difficult to detect.
As in it will learn from it's own mistakes much faster than we ever could.
Polocing such technology and the generated content created by it would become a nightmare.