It's always worth entering a market if you have an edge or idea that nobody else has, and you think the market would utilize it. That's sort of the point of startups :)

Disclaimer: I actually worked for (and helped found) a company that used AI tools as a complimentary piece of the language learning process. The company closed doors early last year. Happy to discuss further if you'd like - our approach was quite radical in nature but the progress our students made was incredible.