I think that the author was using Anki incorrectly, and that led them to the spurious conclusion that "Anki is dead". I also have attempted to use Anki this way- using someone else's deck to try to force myself to learn something new. But that doesn't work, because it is just memorizing random symbols, as they noted in the article ("The enemy is the static card"). For example in maths learning, memorizing arbitrary terms, symbols, etc is useless. However, once I am introduced to a concept for the first time, then I add it to my Anki deck so I can make sure I remember it. The key is the context, and writing terms / definitions etc that speak specifically to me. I still need to work out different variations of the concept to understand it, and that's not something that Anki can help with.
I haven't used Anki for language learning, but I imagine that if I did, it would be to add some new vocabulary I had just learned from a book, conversation, film, etc. I don't think it would help me learn a language from zero though- that would require practicing it.
In summary, Anki is great for reinforcing something you've just learned, but you can't reinforce your way into the context that is necessary to truly understand something.
I couldn't give you a percentage, but I made most of my own cards, including all of those 2000+ kanji cards. There's lots of debate in the language learning community about vocab cards or sentence cards, and generally the ideal is the sentence cards, as it provides the context that helps you use is naturally (as opposed to literal translations from your native language).
> I still need to work out different variations of the concept to understand it, and that's not something that Anki can help with.
But imagine if it could!
I guess the best way to start is just to create a new deck in it with one card and then go from there. I already have a daily review habit, which is the most important part.