[comnetxr]

There's additional piece to this that you are missing: while the classical simulation is _hard_ (i.e. increasingly hard for larger and larger number of qubits or circuit depths), it _can_ be computed with enough computational power for small number of qubits <=50 and depths<=20. (To get the classical simulation to 50 qubits was an achievement in itself and required a huge amount of compute power provided by google, without which they'd probably be only able to compute it for 30-40 qubits.) And where the classical computer can compute the result, the quantum computer does get the same answer with some probability (not a particularly high probability in absolute sense, but much higher than you would expect than if the quantum computer didn't work.)

[comnetxr]

Therefore the win here is that they have verified that a 50 qubit quantum computer "works" (success rate > 10^-3 > 0.) No classical computer could verify a 100 qubit quantum computer in the same way (but you could verify various 50 qubit subsections of the 100 qubit quantum computer). Alternatively, if they had two such 50 qubit devices (and presumably they will soon) they can verify the second one with the first much quicker than they can verify the first with a classical computer, so in that sense the quantum computer beats a classical computer at some task.

[trucho]

you lost me at "presumably they will" ...