I think your mistake is thinking LiDAR exists to solve the happy day scenario. It doesn't.

Vision is sufficient for the majority of use cases. Where LiDAR comes into its own is in the edge cases because it almost guarantees accurate bounding box detection. Which is where vision is at its weakest.

So I want to know what does FSD do when it sees a billboard of a person or when it is seeing a new object for the first time.