Congrats! I'm actually quite surprised because you must be the first person that learned a language using Duolingo. Most people I spoke with said they only learned how to answer Duo questions, not the language itself.

During my German B1 test I met a person who had only used Duolingo for learning the language. They had successfully passed most of the test... except for the spoken part, which they had already failed once and which Duolingo doesn't really help you with. And based on what I heard, they probably failed it again. So I guess you can learn something with it to a decent level.

On the other hand, I once had trouble repeatedly failing a German lesson so I gave the phone to my German girlfriend. She failed the lesson too, probably because she was answering as a German and not as a Duolingo user.

I’ve used Duolingo quite a bit as a part of my Norwegian training, and to brush up on my French now and then. It’s definitely been effective for me. And I’ve seen others become tourist-proficient in languages with no training aside from Duolingo.

I definitely don’t consider it passive consumption.

Duolingo is golden for brushing up languages you have previously learned, yet forgotten

I didn't exclusively use Duolingo. I also got real world practice. But Duolingo was great for practicing in free moments, and for about 1-2 hours every day. Something that was hard to match with real world conversation partners.

I always tell folks that Duo is a good place to start learning but you need to augment/replace it with other methods/tools after learning basic pronunciation and grammar.