Has quantum advantage been achieved?

Quantum advantage refers to quantum computers solving tasks that classical computers cannot, with exponential scaling differences. Recent experiments by Google, USTC, and Quantinuum have demonstrated random circuit sampling on 53-83 qubits with statistically significant cross-entropy benchmark scores, though only the 2019 Google experiment has been classically simulated. These demonstrations use random quantum circuits as the computational task, achieving XEB scores between 0.05-0.2% that indicate nontrivial quantum behavior. However, verifying these results requires proxies and extrapolation from classically tractable regimes, making the advantage claims indirect. Despite solving useless tasks, these experiments show quantum devices can perform computations beyond classical supercomputers' reach.