Resolves yes if there's a clear documented case where a quantum computer successfully breaks a widely-used cryptographic system (e.g., RSA encryption) before 2030.
1,000I think quantum computers have successfully factored 15 in 3*5 and even 21 into 3*7. This represents breaking idiotically-small-n RSA, so you can resolve YES already. This is why other markets of this kind https://manifold.markets/dieselbaby1337/will-a-quantum-computer-prove-capab try to be a little more specific about the key size and what not.
"Resolves YES if a quantum computer breaks a widely used crypto system faster than a classical computer would break it" would make sense.
Quantum computing is ages away from becoming useful. And now its being discussed if with existence of advanced AIs whether it will be needed in the first place. The way quantum computing works is very different and the purposes it serves is also very different. Quantum computers per se wont replace traditional computers. It will rather solve different types of problems.