Kind of goes without saying when nobody has built a quantum computer of the type we are talking about. No general purpose error corrected quantum computer has been used to do anything because they don't exist yet.
I don't think that's common knowledge. It's commonly accepted truth in the industry, but particularly when most people think of military/spies as secretly X years ahead (pick a number) of what the public knows is possible, the tech sector in general can't be expected to know this. It's good to add this in a thread with a headline that sounds like anyone using ecc keys might have a big problem.
That particular demonstration is interesting, but it's not a general-purpose error-corrected quantum computer. It's a single-purpose quantum computer that simulates a quantum process with fewer gate operations than a classical computer needs to simulate the same process.
That's not true. There is such a thing as a completely general set of quantum gates, which combined with qubit memory, would make for a general quantum computer capable of computing any unitary transformation to a certain accuracy.
No quantum computer has ever been used for that purpose in real life, however.