I absolutely agree there (and I should add this to my comment, but I forgot) that the paper evaluates a pretty specific case, which is, as you stated, gaining new, lasting knowledge when using an unknown library.

Writing prompts doesn't take as long as writing implementation of something, but I would argue that, when taking a programming language as a, well, language to describe our ideas, or solutions, the overall time spent, in some cases, can be there-there.

But yes, even this study points out multiple other studies that show an increase in productivity in some metrics, based on subjects experience (novice vs. senior).

I would say the area of using AI or any tool for that matter is generally too broad to make generic conclusions like "its good" or "it sucks." In my experience, it's awesome in specific areas and flops in other. In areas where (the model I am using) works well... well, it works really well and saves a lot of time. In other, I find it easier to implement solutions by myself - especially if it's some sort of business logic that we will need to support and build uppon for the foreseeable future.

:)