> Bitcoin entrepreneur Ben Sigman pointed out that ECDSA, vulnerable to Shor’s algorithm, would require several million physical qubits to break it. SHA-256 is even more demanding, needing hundreds of millions of qubits via Grover’s algorithm to pose a significant threat.

SHA-256 needing a hundreds times more qubits is wrong. The linked tweet from Ben shows it needing about the same number of qubits as ECDSA.