I have now been speaking spanish for 9 years and have no use for duolingo when it comes to spanish, but I always recommend it as a resource to level up when you are a beginner.
I'm fluent in French and immigrated here about a decade ago, and I wouldn't have done that if not for Duolingo. It didn't get me anywhere close to fluent itself (Assimil was the single best resource, but no one resource can you get you to fluent), but it got me started and it got me committed. For that, I'm grateful.
Of course it is possible to learn a language using Duolingo, just like it is possible to get dates on Tinder, but it's just not a good method. If you're new to learning foreign languages, you'd be better off signing up for a course (but that costs time and money), and if this is your n-th foreign language, then you'd rather get a book and some boring flashcard app.
I booked the the single remaining one last year and shortly before the start they announced they will not run it anymore and instead do online classes only. Apparently the rent is too high and it just isn't viable anymore.
It sucks all around :/
Not stuff that's actually useful.
But it still builds vocabulary and is better than nothing for the price.
Just by knowing a few key phrases in the main categories and the probable answers to those in a language will help you get by a lot better than "I like to ride my bicycle in the rain on the weekends" :D
Functional fluency over grammatical competence.
plants for week walk My every uncle takes a his
I was still in the middle of Spanish course when I realize I can sorta kinda watch and understand some shows, so I watched. (The watching itself then made me progress mucj further, but it would not happen without duolingo).
I still use Duolingo almost daily to have some continuous language exposure, for which I still find it useful (especially as the gamification helps with staying engaged). It has its limitations but it does help me. Just to give a bit of a counterpoint; I find your statement a bit overly broad.
To be honest though, the main thing that puts me off isn't the teaching quality (which is basic/so-so) but the plethora of weird patterns to keep you hooked. I don't buy the "we want you to succeed" justification. Streaks, streak freezes, begging notifications - anything to keep you looking at ads I guess.
The fluency complaint is completely nonsensical. There is no in person class that would make you fluent, there is no textbook that would make you fluent.
It is possible to criticize Duolingo, but the fluency claim kind of show you don't know what you talk about.
But they say they're "the world's best way to learn a language," right there on their homepage: https://www.duolingo.com.
So either no one has ever successfully become fluent in a foreign language (because not even the best tool can be used to successfully accomplish the task), or the tech industry is full of liars and its claims cannot be trusted.
I happen to have a Duolingo account, and was once a customer. I will send an angry message to their support team of AI robbots and hope it gets carried up to the top.
One of the most valuable determinants for learning a new language is regular practice. Answering 30 easy exercises correctly will do more for your language skill than 10 hard exercises of which you only answer 5 correctly.
And easy questions have the added benefit of being less tedious and convincing more people to stick to the app.
Number of people I expect to meet in the future that used "AI first" Duolingo that successfully became fluent in a new language: 0
They don't even really have a functional product to begin with. Meaning that it can take the average person and help them competently speak a new language in a reasonable time frame. Vibe coding I guess can't make it any worse....