The world digital economy is worth more than 20T and we're concerned about an asset <2T!? If quantum breaks the highest form of encryption we have today, we have bigger problems at hand.
The signature scheme used by bitcoin is far from the best encryption we have today, and more resistant to being updated than most more important things. So it’s an interesting novelty.
I think a lot of the confusion in these threads comes from treating quantum risk as a single binary event.
A centralized system can often rotate credentials, patch infra, and recover operationally. A decentralized system with exposed legacy keys and social coordination constraints is a very different problem.