Plenty of people enjoy Duolingo. And I wouldn’t say it’s a dead end any more than simple picture books or a total beginners class. Will it turn you into a fluent speaker? No, so what.
My impression of duolingo was strongly influenced by a former PM who said basically what OP said without any hint of ill will in their voice. Duolingo discovered that it was easier to reward-hack short term signals of language learning instead of scaffolding those signals into longterm language learning. Today it’s essentially Candy Crush for people who think they’re too smart for Candy Crush.
That’s not even a diss, it’s just The Way Of The World when you are directly rewarded for growth and retention and very indirectly for language learning.
> No, so what.
Because it promotes itself as a platform to learn fluency. That’s why it’s important to recognize its limitations.