I understand the difficulties you've had with getting immersed with German, given that my target language while in the military had very little content period, let alone things I was particularly interested in. It might be worthwhile to look for German translations of works you've read/watched in your native language or English, though, if you're still interested in learning it.

> I feel duolingo has the same problem - no matter how much you "learn" with the app, it won't ever stick unless you can practice somewhere in the real world.

Yeah, there's too many methods you need to use to facilitate language learning and while Duolingo can potentially fill a lot of these holes, I don't think it can be your holistic one stop shop.