Which is the real reason agile is so much more effective than waterfall. The beginning of the project is when you know least about your project, so naturally you should be able to evolve the specification.
Maybe it is that LLM coding makes it easier to loop back with little regard for development cost. When you can spend an hour to fix what would have been hampered severely by technical debt late in the process - are we starting to omit optimizing for proper SDLC?
Generally I find that agile works because getting a really clear spec is so hard. You’re slowly iterating towards a clear spec. What is a finished piece of software if not a completed spec?
100% agree AI based dev is at odds with agile. You’re basically going to use the AI to fully rewrite the software over and over until the spec becomes clear which just isn’t very efficient. Plus it doesn’t help that natural language cannot be as clear a spec as code.