Relevant quote from the briefing, which indicates they have not yet reached error correction takeoff velocity:
> It is known in the field that, when the physical error rate of qubits is high, the probability of logical error increases with increasing system size, whereas when physical error rates are low, increasing the system size leads to the desired exponential suppression of logical error. We feel that we are currently in a ‘crossover’ regime between these scenarios, in which increasing system size initially suppresses the logical error per cycle, but would, with increasing size, later increase error rates. Therefore, it is imperative that we continue to improve both qubit performance and system scale.
So this result is not yet the major breakthrough that would be required to build a scalable quantum computer.
> It is known in the field that, when the physical error rate of qubits is high, the probability of logical error increases with increasing system size, whereas when physical error rates are low, increasing the system size leads to the desired exponential suppression of logical error. We feel that we are currently in a ‘crossover’ regime between these scenarios, in which increasing system size initially suppresses the logical error per cycle, but would, with increasing size, later increase error rates. Therefore, it is imperative that we continue to improve both qubit performance and system scale.
So this result is not yet the major breakthrough that would be required to build a scalable quantum computer.