I have a theory that reviewing written vocab actually helps your listening too, if you read the cards with an inner voice that has good pronunciation.

The people whose listening doesn't improve from Anki, at least a little bit, probably don't hear things in their head right. It doesn't match the real spoken word.

I've been told I have very good pronunciation (at times indistinguishable from native!) and I'm confident that what I'm hearing in my head when I read can't be any worse than what comes out of my mouth. So I find that vocab training in this style has increased my understanding of spoken vocabulary. Obviously not as well as targeted listening study, but meaningfully.