So we need a mechanism that makes this identity verifiable, maybe you get a unique identifier from the identity service, so you can block the account. There is no mechanism to report you to say, the identity service (this is a bot), so you manage your own block list.
The risk here is fingerprinting, your id can be cross referenced across apps. Maybe here is where you implement a zk proof that you're who you say you are.
You've identified a problem that unrelated systems also have. Like banks and identity theft. This solution isn't responsible for causing that problem.
"How will the AI be detected? By another AI?"
However a platform likes to. Let the best platform win.