That's an example of what I meant by problems that "are specifically contrived to show quantum supremacy". Scott Aaronson explains this quite well:

https://www.scottaaronson.com/blog/?p=4317

> So, tl;dr, the quantum computer is simply asked to apply a random (but known) sequence of quantum operations—not because we intrinsically care about the result, but because we’re trying to prove that it can beat a classical computer at some well-defined task.