[sporkl]

I don't remember the details, but the reason the 2019 paper was challenged was because Google did not take into account quantum simulation optimization techniques when estimating how long the computation would run on classical computers. I wouldn't be surprised if there's a similar situation here, where unconsidered optimizations prevent this from being quantum advantage.

[klyrs]

As I recall, they did not take the error rate into account. The result was dashed by somebody looking at their error rate and saying "we can compute that distribution to within 5%* with a classical computer." One would hope that they learned from this, but historically, supremacy claims have been rather short-lived.

* number pulled out of a hat

[oldgradstudent]

The main challenge for the Google quantum supremacy result was that calling it a computer or what it does a computation never made any sense.