Rapid prototyping is certainly a good use case for AI, but I don't see it really working for larger work projects where design complexity make be an issue.
Certainly considering how all the parts interact is part of brainstorming alternate system designs, but I think high level architecture / project-decomposition (design) has to occur before prototyping (coding) would be applicable.
Design/architecture by vibe coding doesn't sound good, but using AI to brainstorm different architectures (before any coding begins) might be useful.