Great, you've just boiled down how online services are making money from their applications. Company x online uses x popular tactics for making money off of the

Great, you've just boiled down how online services are making money from their applications. Company x online uses x popular tactics for making money off of the services they provide, shock. It's a bit of a boring story really. Yes AI is 'so hot right now' so why not leverage it? It's hot for a reason and maybe just maybe, it is actually beneficial to the product you provide, so why wouldn't you implement it. I can see another angle if they didn't where people would start to say Duolingo is starting to become dated, due to lack of features such as AI/ML.