"Google Confirms 'Quantum Supremacy' - Completes 10,000 Year Calculation In 200 Seconds" ... grandson of Cray 1, but not something for your on-line gaming system.

https://www.nature.com/articles/s41586-019-1666-5More important, was to keep it stable for 200+ seconds. Also a practical quantum computer would have redundant qbits.

Here is how to quantify this ...

54 qbits equals 2^54 computations or 1.8 x 10^16. But a 40 character, 36-letter alphabet code has 1.8x10^62 combinations. So this new machine would take 200 x 10^46 seconds to run or 6.3x10^40 years. So a simple cypher is still impervious to brute force. And in physics, there is nothing faster at these particular algorithms (parallel decoding) than a quantum computer. So even a simple cypher will be forever impervious to brute force decoding. What Bletchley Park did, wasn't beat math, they beat bad German use of the Enigma.