Anki is great... however:
... having used it for the last 4 years to try to memorize vocabulary in certain languages (Spanish & French, recently started Chinese), I think it's a base layer... (much like how Bitcoiners like to talk about BTC's Blockchain). Reasons:
1. I've tired of it. I need a layer that makes me excited to use it.
2. I've found it far-far less useful for learning other things than rote vocabulary memorization. It needs a layer that makes it easy to store and "pull up" everything I need to know.
In my opinion people often make the mistake of using Anki to memorize one-to-one translations of foreign words. It is more effective to use it to learn the mapping of whole sentences.
For every word you want to learn, add a few idiomatic and representative sentences in Anki. You can do the same for every new grammatical concept you want to learn.
And don't forget to use Anki's text-to-speech tools to practice listening as well as speaking.
Does it replace other forms of learning entirely? No, but it can be a great component of learning a new language.