Ask HN: Are people generally interested using LLMs for learning purposes?

When LLMs first hit the scene I had assumed one of the big use cases would be to use the LLM's vast knowledge to teach people about subjects they are interested in. I thought there would be some hot app that let you suggest a subject (e.g. CUDA programming) and the app would interactively teach you and test your knowledge along the way. How come this use case never took off?