Where do you find the words to add to your deck? I add words discovered in lessons - which are great for a proper context - but using words from internet sources (the news, etc.) is time consuming and means I keep seeing words from a few narrow niches (politics, economics, slang) without any understanding of how they'll be interpreted.
Get used to it. Learning a language is time consuming. Nobody ever learned a language by studying it 30 mins per day.
At a beginner level, one can find words through the grammar textbooks and the like.
At intermediate+, you find words through material that you find. For example, news, tv shows, songs, and the like. It's up to you from here on out.
> I keep seeing words from a few narrow niches
The trick is to vary your resources. Read the news, but also read a short fiction book, watch a comedy tv show and then a drama, etc. You should also find resources at your level. If you are a beginner, don't bother reading the news. Even if you look up all the words, they're usually niche and will not help you that much.
One way to combat this is to find a list of the 2k, 3k, 5k most commonly used words and add them to your anki deck.
What I do is I add unknown words from my daily conversations with native speakers.
> without any understanding of how they'll be interpreted
If you see a word in a sentence from a native source, that's a pretty good way to see how it's used. You can also cross-reference with a dictionary or by asking the native speakers you practice with.
When you add a word to your anki flashcard deck, you need to also add sample sentences. It's borderline useless to learn a niche word without examples of how it's used.