In my opinion, reading texts is more efficient than listening to conversations. It's basically "on demand language streaming", you can slow down or speed up as desired.
The last duolingo I used was just trying to get humans to solve its foreign-language reCaptcha material.
Out of disgust for the solutions that existed, I went so far as to start working on my own Memrise style app which understands enough German grammar to generate English/German sentence pairs, so you can practice sentences with nouns/verbs/adjectives swapped around.
So it shows you the first sentence and you translate:
I lay the pen on a table. Ich lege den Stift auf einen Tisch
The pens lay on the table. Die Stifte lagen auf dem Tisch.
Or it shows you a present tense and you make it past:
Ich lese ein Buch. Ich habe ein Buch gelesen.
It was really effective at hammering in the edge cases of grammar (you'd practice maybe 500 sentences an hour). Though I got kicked out of Germany due to visa trouble and life took a different direction, and haven't touched it since!
Duolingo is but a tool among many. For one thing it tends to not force you to repeat enough, and for another the grammatical explanations are not that elaborate and easily ignored.
But for basic drilling it's great and I would prefer it over most other tools. After a point, of course, other things like reading, listening and writing become more important and efficient.
As I was under a bridging visa that meant I was now there illegally.
When I contacted them to find out what the hold up was, they told me what happened and that I was now there illegally and needed to leave immediately, so I did.
After the mistake was found out the visa office were apologetic and offered to give me a visa again, and the criminal case against me for overstaying was dropped.
But it was such a disruption to my life I no longer have interest.
Until I dealt with the German government and professionals that deal with the German government (taxes, visa etc), I had no idea how lucky I have it as an Australian.
A lot of the stories I formed my opinion on were second hand, issues my friends were dealing with; such as the Kafkaesque situation of registering for residency in a city, but not being able to rent without residency paperwork, and not being able to get the paperwork without a fixed address.
In Australia, it's just not a thing at all. If the Government tried to make us register with the city we're living in, we'd tell them to fuck off. Albeit in less polite language than that.
In the eight years I lived in New Zealand (as an Australian) I interacted with the government once a year to file my taxes, filled out two census forms and had a ten minute appointment to convert my Australian drivers license to one from New Zealand. It's not just that the interactions were easier, there just weren't any.
This is the type of problems that come up. I don't understand, though. There are multiple ways to get an address in Germany without a residency permit. You can also rent places without a residency permit. Maybe the person that encountered the issue you describe wanted to rent one specific place which requires a residence permit, and didn't want to do any other (temporary) thing to get an address.
But the issues don't exist in the first place in AU/NZ (and presumably UK/US though I can't speak first hand do that). Even if they did, they'd be solved in a much more straightforward manner. I guarantee a similar form here, even though it would never exist, would accept "address pending" as a valid answer.
I'm not trying to say the German way is wrong, but you have to understand how crazy it seems to a foreigner.
If a landowner wants a residency permit, which I've never seen, then maybe that was an ouvert way of saying no?
Duolingo is completely useless in my opinion. It doesn't teach you anything about grammar and doesn't teach you much vocabulary. It's more like having random conversations with a native who doesn't actually know much about their own language, except you will never ever be able to converse with a native after only using Duolingo.
It's a waste of time just like "Roseta Stone". Both try to tell you it's the "easy way" because it's how babies do it. Well babies spend years immersed and completely helpless without language until they finally get it. Even if you could go through with that, would you even want to? As an adult you would be stupid not to use the best tool you already have for learning things: your mother tongue.
If you're serious about learning a language you need some way to learn vocabulary, a good book or books in your language to teach you grammar, and lots and lots of material in the new language: books, news, films, radio etc. You will not be able to learn to speak without a sympathetic native, though.