Where does this fail? Interpreting test bench results as direct proof of viability for portfolio optimization is an excessive extrapolation of laboratory data, ignoring the complexity of real markets.
A 64-qubit system, even on 250 S&P 500 assets, cannot simulate the full dynamics of an institutional portfolio and its regulatory requirements.
The weakest link is the transition from proof of concept to operational proof, which would require thousands of assets and an extremely low error tolerance.
For example, a fund manager must navigate liquidity constraints and latencies that current quantum experimentation cannot realistically model.