This claim is just not true. And gets tiresome. You roughly end up where those courses claim to be in reading and listening - depending on language it can be over B1. (No course finishes B2, some do have B2 content). I ended up being able to watch some (not all) netflix series in foreign langue and I was in early B1 section. I clearly learned.
I speak 4 foreign languages, at (fully tested through exams like the DALF, DELE, Goethe Institute) levels of C2, C1, C1 and B2. Take an actual test proving your knowledge and get back to me.
I've spent a lot of time with Duolingo learners. They're all pre-A1. You're just lying to yourself to make yourself think your phone addiction isn't "that bad." Take a real language class.
It is simple. I do not want to and have absolutely no reason to take the language class. So, why would I? They costs money, time and are not something to look forward to. I got actual visible measurable results. Why would I changed?
Besides, language classes also fail. Going to language classes for years and not being able to use the language in any practical situation was always fairly common result.
> I've spent a lot of time with Duolingo learners. They're all pre-A1.
I know people who tested B2 after doing nothing but Duolingo German. And like I said, I can watch Netflix shows and read books in language I used Duolingo for. That is definitely something.
You also dont have to pay.