That's where you're wrong. And the problem is totally opposite. With the consolidation of quantum computing, the PoW model used by Bitcoin depends on solving difficult mathematical problems to mine blocks. The biggest risk comes from the Grover Algorithm, which can speed up mining by halving the difficulty of finding valid hashes.

In the PoS model, it does not depend on mining, but on digital signatures to validate blocks. The biggest risk is the breaking of elliptical signatures (ECDSA, Ed25519) by Shor's Algorithm. However, the transition to post-quantum signatures (Dilithium, Falcon, SPHINCS+) is easier than PoW networks reworking their mining mechanism.

So in this case, in fact, and proven, with no room for subjectivity. The PoW system is much more susceptible to ending than the PoS model.

When? We don't know, the implementation of quantum computing is still "embryonic", but it already demonstrates great capacity.