Quantum data links seem great for establishing shared symmetric keys, which are much more practical than asymmetric keys for fast de/encryption. However the ke

Quantum data links seem great for establishing shared symmetric keys, which are much more practical than asymmetric keys for fast de/encryption. However the key sharing process still relies on some process like Diffie-Hellman, or sending a PGP encrypted symmetric key generator. Are there any key advantages to using QKD over these methods?