> OTOH, the cost to this progress not having been earned is pretty high, too: He takes a lot of AI-generated boilerplate for granted now without understanding it or the concepts behind it, so when the AI gets it wrong or forgets it, he is unable to notice what's missing.

How materially different is this from "copy-pasted boilerplate from an example on a website that isn't fully understood"?

I've personally found one of the biggest advantages for learning a new stack with ChatGPT is being able to say "hey, how do I modify this boilerplate for [specific piece of functionality]" or "hey, I have this code and I'm getting this error, what should I try" vs just trying to find websites with other examples of slightly-different boilerplate or trying to start from square 1 (which would often mean dedicating days or weeks to less-immediately-relevant tutorial foundation projects).