Is the time to develop production code being reduced if they stop slinging code over the wall and only use AI code as inspiration?

Is the time to develop production code reduced if AI gen code needs work and the senior engineer can't get a clear answer from the junior as to why design decisions were made? Is the junior actually learning anything except how to vibe their way out of it with ever more complex prompts?

Is any of this actually improving productivity? I'd love to know from experts in the industry here as my workplace is really pushing hard on AI everything but we're not a software company