I’ve seen some horrendous systems where you can tell a bunch of totally separate visions were frankenstein’d together

My experience has been that using AI only accelerates this process, because the AI has no concept of what good architecture is or how to reduce entropy. Unless you can one-shot the entire architecture, it's going to immediately go off the rails. And if the architecture was that simple to begin with, there really wasn't much value in the AI in the first place.