> If I need to be a domain expert anyway, the value of the tool goes down by orders of magnitude. Same if I need to first break the task down into pieces and keep reviewing all the output. That sounds to me like >80% of the work I'd need to do anyway.

You absolutely don't. You only need to be roughly aware of what the code needs to be doing. Similar to how a software architect historically didn't personally oversee every line of code in an org, only it's overall structure. The implementation specific details can be left to the AI.