Another way of putting it would be "pretty simple and quick - if you can achieve a completely infeasible number of qubits".

That is to say, it's an algorithmic overhang, the knowledge how is available but held back by not knowing how to achieve the hardware needed.

The risk being that someone could discover "how to make qubits" tomorrow, and although (because it's hardware) it might take a short while to turn that into an industrial qubit pipeline, we don't yet actually know yet that it's mechanically impossible to do.

Indeed, in fact I'd consider that an understatement of the situation.

It will probably be earlier than fully crack SHA1 (aka finding the preimage). And SHA1 is already considered a problem for at least a decade.

If post-quantum cryptography algorithms are already there, I can see EC being abondoned soon