It really depends on how you define "complete". It's possible the answer in "not large at all" if we're looking for high-quality, reliable, user-friendly software that works near perfectly after being written, tested, deployed completely by AI with no human intervention.

People who try to get AI to do a lot of un-manned work seem to have a bit of a bias toward viewing LLM work as "good" or "good enough" in a way that they wouldn't have accepted in the pre-AI era.