To use a Geohot-inspired analogy, what we have now is like the Google self-driving car of 2010. It works most of the time, yet sometimes fails in unpredictable ways. So you need a safety driver behind the wheel to constantly watch what it's doing (the code review).
A real AI agent would not need a safety driver. We don't have that but many people are basically saying "fuck it, I'm just going to set this car off on its own and see what happens". And sure if you're prototyping it's not dangerous. But for production systems that is dangerous.