I see it at our place that seniors get more productive but also that juniors get faster on track and more easily learn the basics that are needed and to do basic tasks like doumentation and tutorial writing. It helps both groups but it does not make a 100x coder out of a newbee or even code by itself. This was a pipe dream from the beginning and some people/companies still sell it that way.

In the end AI is a tool that helps everyone to get better but the knowledge and creativity is still in the people not in the input files of chatgpt.

The effect I have observed is that it's fairly good at tricking people who are latently capable of programming but have been intimidated by it. They will fall for the promise of not having to code, but then wind up having to reason and learn about the LLM's output and fix it themselves, but in the end they do wind up with something they would not have made otherwise. It's still not good or elegant code, but it's often the kind of very useful small hacky utility that would not be made otherwise.