An experienced UI developer probably would have still been faster than I. That puts me closer into the junior camp (eg I wouldn’t really know where to start and just start by stumbling around) when I’m by myself but an LLM lets me get back closer to my level of expertise and velocity.

We might just have to agree to disagree. I believe that an experienced developer brings instincts and stacked skills even to domains where they have never touched.

In other words, I don't think that you temporarily regress to "junior" just because you're working on something new. You still have a profound fundamental understanding of how technology works and what to expect in different situations.

This reminds me of the classic "what happens when you type google.com into a web browser" question, with its nearly infinite layers of abstraction from keyboard switches to rendering a document with calls to a display driver and photons hitting your visual receptors.

We might just be quibbling over terminology, however.