Did you want to learn Mongolian or did you want to play a video game where you pretended to learn Mongolian. Because if it was the former, plenty of resources have been available for you for years. You could have walked into your local bookstore and bought a textbook, hired a tutor on italki, downloaded an anki deck, listened to MNB broadcasts etc. etc.

I think LLMs are pretty similar to DuoLingo. It is a tool that makes you feel like you have accomplished something without you putting in the work you need to actually accomplish anything. Worse still, you still need to put in the time. So in effect you end up wasting a bunch of time without learning anything new. These machines, are dopamine generators, kind of like cigarettes, or slot machines.