I did actually end up quitting Duolingo a few weeks ago. I always made my lessons ‘legendary’, giving them a gold colour, which is a nice visual indicator of ‘yeah, you did it!’. I had done so for all the lessons I’d done.
Then they updated all my courses and nothing was gold anymore. That broke me. It’s a lot of extra work I put in, and just like that, it was all gone.
Sure, it means nothing - I still learned whatever content was there. But it felt like a slap in the face.
I don’t miss the routine of Duolingo at all. I used to do a few lessons right after waking up in order to get my brain going, so now I just play a puzzle game instead (if anyone has any recommendations, let me know!).
As for Duolingo’s funny sentences - I may have a little bit more insight there. Back when courses were still developed by volunteers in the community, I was one such volunteer for the Dutch course. There’s a few reasons for them.
You’re never going to use the silly sentences in real life… but that’s pretty much exactly the point. There are sentences you’re going to hear a thousand times (“Hi, how are you?”) and that means you might be learning a sentence, rather than the parts of it - which you could then apply to new sentences you construct yourself. If you only learn the sentence “Hi, how are you?”, you’re not going to know that “Hi” can also be used in sentences like “Hi, I’m new here.” Silly sentences show you the language in a new way.
And if they’re funny, they might stick better, and you’ll recall them easier. Then you just have to substitute the silliness for whatever you are trying to express.
Of course on the business side of things, the sentences serve a good function too - they set the app apart from others. They are a marketing trick. “Duolingo uses silly sentences to teach language? I gotta see this for myself.” Or: “I want to learn a language… oh hey I heard Duolingo uses silly sentences, let’s see what that’s about”.
No worries, for all the languages I did on Duolingo, I have either a good basis to start from already, or I have access to a native speaker
With the exception of Japanese, but my bookshelf full of Japanese textbooks and the multitude of other online sources has taken care of that 


So no complaints there, either.