Ask HN: What's up with the influx of language learning platforms these days?

I'm a dev, and for the last one year or so I've been getting job offers from language learning platforms, to the point where 1 in 4 job offers is from one of these platforms. What's up with this influx? Are people really that interested in learning a new language online? How are they profitable? I was thinking that maybe they use the people to train AI models in different languages(?). What do you think?