That's the failure to automate. The AI isn't telepathic, so agentic engineers not automating this stuff is skipping out on the engineering part.
You setup the environment and then you do the work. Unless you are switching employers every week, you invest in writing that stuff down so the generation is right-ish and generate validation tooling so it auto-detects the mistakes and self-repairs.
sometimes you write the feature and write it well so it's reusable.
imagine you have to implement a specific algorithm for a quantum computer.
There's no value setting up AI to do the writing for you. That might be orders of magnitude harder then writing the algorithm directly.
For highly specialized one-off features, it doesn't always pay off.
On the other hand, if all you do are some generic items that AI can do well... then I'm not sure you're going to have a job long term, your prompts and automation will be useful for the new junior hires that will be specialized in using these and cost effective.