I think the major problem with Duolingo is that it’s really bad at teaching grammar, so you don’t really learn how to construct new sentences on your own. (I found that it does even worse than not teaching grammar: it actively obscures grammatical concepts, so I later had to unlearn things, but that’s a separate rant.)
In the list of activities you mentioned, you didn’t mention any activity that forces you to construct new sentences. Wanikani doesn’t teach the language and falling asleep with news is the most passive thing possible. So IMO the answer is no, you can’t become good in a language if you don’t practice constructing your own sentences.