> I'm curious: what have you actually learned from using LLMs to generate code for you?

I learn whether my design works. Some of the things I plan would take hours to type out and test. Now I can just ask the LLM, it throws out a working, compiling solution, and I can test that without spending my waking hours on silly things. I can just glance at the code and see that it's right or wrong.

If there are internal contradictions in the design, I find that out as well.