This is really the point: We build systems and processes which help ensure that we get reliable outputs (bridges) from unreliable actors (human workers). The point is not that we will one day replace all of these processes with AGI. The point is that we will still want processes and systems in place to ensure reliability.

The importance of safety process is largely a function of the risk of failure (ie, how unreliable the production process is) and the cost of failure. If you've got a very reliable production process, perhaps you need less safety process. But if the cost of failure is measured in lives, you're still going to want to have checks in place, regardless of who/what is responsible for designing the bridge.