I agree with this perspective. Quantum computing mainly targets core encryption algorithms: ECDSA (Elliptic Curve Digital Signature Algorithm), which is used to generate private keys and sign transactions. Both BTC and ETH rely on ECDSA, and once quantum computers become powerful enough, they could use Shor's algorithm to efficiently crack private keys, reverse-engineering them from public keys, leading to stolen funds. For now, it seems there shouldn't be any major issues within 5 years, but in 10-20 years, there's a probability of threats emerging; after 20 years, the likelihood of threats is very high.