It is an interesting possibility that must be considered. Only time will tell. However I disagree.

I think complex systems will still turn into a big ball of mud and AI agents will get just as bogged down as humans when dealing with it. And even though re-build from scratch is cheaper than ever, it can't possibly be done cheaply while also remembering the millions+ of specific characteristics that users will have come to rely on.

Maybe if you pushed spec-driven development to the absolute extreme, but i don't think pushing it that far is easy/cheap. Just as the effort to go from 90% unit test coverage to 100% is hard and possibly not worth it, I expect a similar barrier around extreme spec-driven.

Clarification: I'm advocating clean code in the generic sense, not Uncle Bob's definition.

In my experience large scale automated refactoring of code is something that works reliably for the last 3-4 months.