Great observation piece. I particularly like your observation on the emotional impact of the app. I would not put everything on the app, but I can see how the app set up condition for frustration and mindless rush.

I hope you give the company feedback. This would help them improve their service (content, usability, learning experience, etc.). However, improving the app can incur costs, and their funding will likely come from ads and subscriptions. So, it is understandable and lawful for for-profit company to drive us towards subscription until there is a regulation for ads use. That said, I am not saying it was fun. I have a girl who plays Duolingo. I would take this over Roblox 😅

I do think that the app can benefit from milestone check to test if a user really learn anything or just rush through. And since the app is gamifying learning, they may want to give a “penalty” or set the user back to the lesson that they quickly skips through and have yet carefully learn. That may help slow down the rush.