I think this exposes a pattern, but not necessarily on the subject or antithetical to OP's point. I interpret the above passage to implicate that we lose abilities as we adopt tools that can do it for us, but writing specifically stunts our ability to memorize facts. I would argue that this enabled us to spend less mental energy on memorization but on processing information instead, able to do more complex calculations. This doesn't negate OP's point that by using LLM's we give up another kind of ability to a tool, in the case reasoning.

Now whether or not this will in the abstract become leverage for another type of skill or multiplier is to be seen.