That’s because they can’t be.
People assume they’ve already figured out how AI behaves and that they can just mandate specific "proper" ways to use it.
The reality is that AI companies and users are going to keep refining these tools until they're indistinguishable from human work whenever they want them to be.
Even if the models still make mistakes, the idea that you can just ban AI from certain settings is a fantasy because there’s no technical way to actually guarantee enforcement.
You’re essentially passing laws that only apply to people who volunteer to follow them, because once someone decides to hide their AI use, you won't be able to prove it anyway.