I'm surprised more people aren't talking about the recent announcement that Duolingo is replacing contractors with AI.
https://www.theverge.com/news/657594/duolingo-ai-first-repla...
https://www.theverge.com/news/657594/duolingo-ai-first-repla...
Duolingo's users are sticky so long as the brand ideology holds: "if you want to learn a second language, play duolingo".
Also, Duolingo CEO Luis von Ahn also founded ReCAPTCHA. Every idea this man has capitalized on has been made obsolete by the advance of AI.