Comment by jasperry

One of the primary uses of public-key encryption is key exchange at the beginning of a session that is subsequently encrypted using symmetric encryption. That's how every TLS session works, because public-key encryption is too slow for large amounts of data. Since QKD is a solution for key exchange, it can replace public-key algorithms in this respect.

The other main application of public-key encryption is digital signatures, which is vital for certificate checking and identity verification in general. At first glance, it seems QKD won't solve that, as you said, but I haven't looked into quantum research relating to signatures.

Quantum computing and cryptography research is important, but are some researchers taking advantage of hype to stay funded by letting people think practical applications are closer than they really are? Possibly. Nonetheless, the research is important.