"Quantum supremacy is the potential ability of quantum computing devices to solve problems that classical computers practically cannot." From: https://en.wikipedia.org/wiki/Quantum_supremacy

IBMs responce: "We argue that an ideal simulation of the same task can be performed on a classical system in 2.5 days and with far greater fidelity. This is in fact a conservative, worst-case estimate, and we expect that with additional refinements the classical cost of the simulation can be further reduced." From: https://www.ibm.com/blogs/research/2019/10/on-quantum-suprem...