I have been pondering this and I think it's likely a gap that will get filled sooner or later.
Right now there's just so much value in building LLM tools for experts that everyone is focusing on that. But surely at some point we'll have bespoke harnesses that exist exactly to solve this kind of thing.
I think this can start with constrained problem spaces like "you are a WordPress developer, you solve problems for people with enough expertise to know they are looking for a WordPress developer" and incrementally expand from there. Maybe I'm naive but I think you can probably get pretty far with this today just by writing loads of skills and picking the right technical preferences to encode in them.
We already have these, and have for a while. Replit and Bolt exist for exactly this case. Not sure why GP didn't direct their friend to these tools (or if these tools are somehow the ones that failed in this example). In my experience, Replit and Bolt (and other similar tools) are quite good at this kind of 0->1 kind of thing.
Yeah there's lots of companies out there that promise that people can build a website quickly, often using WYSIWYG / drag / drop interfaces, I bet they already have AI integration to speed things up. ("I bet" because I don't actually use those services.)
I think people are better helped by using those services than going a level lower and using LLMs directly.