But if anyone ever builds such a quantum computer it isn't necessarily the end for public key crypto because there is a workaround that will work on classical computers, and that is to avoid trapdoor functions that can be broken by Shor's algorithm. So if a quantum computer comes along that can break, say, 256 bit RSA, we can save public key crypto by everyone switching to a different algorithm. That's the idea of post-quantum cryptography. And although RSA might be broken by a future quantum computer we can still have some sort of public key cryptography.
From the looks of this blog post, though, one of the new post-quantum public key algorithms can be broken. At least it could be if anyone ever makes a big enough quantum computer. And there's still the possibility that someone will find a trapdoor function that will be quantum resistant, so it isn't the end for all public key crypto.
tl;dr One more public key scheme might have fallen to a quantum algorithm. But the quantum hardware isn't there yet, so it's OK for now.