Prime factorisation is indeed nobody's primary idea of what a quantum computer will be useful for in practice any time soon, but it cannot be denied that Shor's algorithm is the first and only method of prime factorisation we have discovered which can finish in realistic time with realistic resources.
And that means that RSA is no longer as safe as it once was, justifying the process of finding alternatives.
Check it, yo. In the 90s all the articles and rumors around quantum computing were exactly the same. Exactly.
Whenever I hear about some new quantum computing breakthrough, I spend about five seconds wondering if it's real and then I feel very nostalgic because no, it never is.
Except quantum computers do indeed exist right now, and did not in the 90's. Sadly, the hype and corporate interests still make it difficult to tell truth from nonsense.
Of course. Not a single quantum computer has done anything but test programs and quantum-specific benchmarks. Until a quantum computer finally does something a normal computer regularly does, but faster, we should simply ignore this area.
EDIT: could the downvoters state a single occasion where a quantum computer outmatched a normal computer on a real problem. And with that I mean something more elaborate than winning naughts and crosses, or something like that.
That's a different kind of quantum computer though (which i call the "real" kind). But that needs a while, especially with current risk-avoiding behavior of big corp. We are not even optical yet, not to talk about multitalents like graphene/silicene.
If true, this would in fact be a huge step toward quantum computing at scale, which would revolutionize computing. However, they've claimed this before, and have offered no evidence yet of their supposed discovery.