[perching_aix]

They explicitly cover all of these caveats in the announcement.

Problems that benefit from quantum computing as far as I'm aware have their own formal language class, so it's also not like you have to consider Sabine's or any other person's thoughts and feelings on the subject - it is formally demonstrated that such problems exist.

Whether the real world applications arrive or not, you can speculate for yourself. You really don't need to borrow the equally unsubstantiated opinion of someone else.

[eigenket]

The formal class is called BQP, in analogy with the classical complexity clas BPP. BQP contains BPP but there is no proof that it is stictly bigger (such a proof would imply P != NP). There are problems in BQP we expect are not in BPP but its not clear if there are any useful problems in BQP and not in BPP, other than essentially Shor's algorithm.

On the other hand it's actually not completely necessary to have a superpolynomial quantum advantage in order to have some quantum advantage. A quantum computer running in quadratic time is still (probably) more useful than a classical computer running in O(n^100) time, even though they're both technically polynomial. An example of this is classical algorithms for simulating quantum circuits with bounded error whose runtime is like n^(1/eps) where eps is the error. If you pick eps=0.01 you've got a technically polynomial runtime classical algorithm but it's runtime is gonna be n^100, which is likely very large.