That's half of what that article (which is excellent!) says. Presumably those unused addresses are lost and would lead to some devaluation but not that much. T

That's half of what that article (which is excellent!) says. Presumably those unused addresses are lost and would lead to some devaluation but not that much. The harder to understand half is that if a quantum computer can break the public key before the transaction is verified (which takes some time, by design) then that's also game over, although it's not clear if that's possible or not.