But when you raise the bar to "better than a desktop PC" it is like going from "well the burden is on chess computers to prove their machine really plays chess" to "the burden is on chess computers to prove they're better than humans (and it's not real until they do.)". That is too high a bar.

My only objection is on this suggestion - that they have to find something it's already better at than a desktop PC (with literally billions of transistors).

I quoted the part I objected to.

But scaling laws should predict that you should need many, many more transistors than qubits to beat a gate quantum computer. For an adiabatic quantum computer something similar should hold.