Better languages do not necessarily mean better architectural decisions, or even better performance, unless the humans pressure for that and burn tokens on that. With no engineer in the room, more technical issues will be left unnoticed and unaddressed.

Compare it to visual arts. With a guidance form an artist, AI tools can help create wonderful pictures. Without such guidance, or at least expert prompting, a typical one-shot image from Gemini is... well, at best recognizable as such.