Unenforceable means they can't actually enforce it since they can't discriminate high quality LLM code from hand typed
The hope here is the same hope as most laws: that lies eventually catch up to people. That truth comes to light. But sure, in the meanwhile, there are always dishonest people around trying to flout rules to varying degrees of success. Some are caught right away, some live their entire lives without it catching up to them. That doesn't make the rule unenforceable, that just highlights the limits of rules: it requires evidence that can be hard to come by.