To use a language you need "over-learning". It's not enough to be able to recall a word.

You need to be able to recall it very fast, and that only comes through repetition beyond the "I won't ever forget this" stage. SRS doesn't make a statement about this, and you can still use it to achieve that over-learning, in my opinion. It may be better to achieve it through reading texts in the foreign language because the repetitions are faster.