If you wanted to toss out public key cryptography as insecure, I guess you could use QKE to make symmetric key cryptography more practical. You would have a sec

If you wanted to toss out public key cryptography as insecure, I guess you could use QKE to make symmetric key cryptography more practical. You would have a secure method of communicating your keys, and wouldn't have to worry that your new post-quantum public key cryptography was broken- since symmetric cryptography just isn't vulnerable in the same way.