A use that seems scientifically possible but technically difficult would be to have an LLM help you engage in essentially immersion learning. Set up something like a pihole, but instead of cutting out ads it intercepts all the content you're consuming (webpages, text, video, images) and translates it to the language you're learning. The idea would be that you don't have to go out and find whole new sources of language to set yourself with a different language's information ecosystem, you can just press a button and convert your current information ecosystem to the language you want to learn. If something like that could be implemented it would be incredibly valuable.
I'll probably get pushback on the quality of things like auto-generated subtitles, but I did the above to watch and understand a long interview I was interested in but don't possess skill in the language they were using. That was to turn the content into something I already know, but I could do the reverse and turn English content into French or whatever I'm trying to learn.
Imagine if it was wrong about something. But every time you tried to submit the bug report it disables your arms via Nueralink.
When it can gently nag you via a phone app to study and have a fake zoom call with you to be more engaging it feels like that could get much better results than the current online courses.