> So how do I answer my child when he asks "Why should I learn to do X if I can just ask an LLM and it will do it better than me"

It's been my experience that LLMs are only better than me at stuff I'm bad at. It's noticeably worse than me at things I'm good at. So the answer to your question depends: can your child get good at things while leaning on an LLM?

I don't know the answer to this. Maybe schools need to expect more from their students with LLMs in the picture.