My friend, there’s no solid evidence that this is the case. So far, there are a bunch of studies, mostly preprints, that make vague implications, but none that can show clear causal links between a lack of mental strain and atrophying brain function from LLMs.

You're right, we only have centuries of humans doing hard things that require ongoing practice to stay sharp. Ask anyone who does something you can't fake, like playing the piano, what taking months off does to their abilities. To be fair, you can get them back much faster than someone that never had the skills to begin, but skills absolutely atrophy if you are not actively engaged with them.

My assembly skills have atrophied terribly, and that's ok.

Using LLMs is not moving up a level of abstraction, it is removing your own brain from the abstraction altogether

I wish, but as it stands right now LLMs have to be driven and caged ruthlessly. Conventions, architecture, interfaces, testing, integration. Yes, you can YOLO it and just let it cook up _something_, but that something will an unmaintainable mess. So I'm removing my brain from the abstraction level of code (as much as I dare), but most definitely not from everything else.

we will all become project managers. That's not removing your brain from problem

We know that learning and building mental capabilities require effort over time. We know that when people have not been applying/practicing programming for years, their skills have atrophied. I think a good default expectation is that unused skills will go away over time. Of course the questions are, is the engagement we have with LLMs enough to sustain the majority of the skills? Or is there new skills one builds that can compensate foe those lost (even when the LLM is no longer used)? How quickly do the changes happen? Are there wider effects, positive and/or negative?

I mostly referred to skills, not brain function itself.