This was a bit disappointing article by Quanta standards, pretty much just felt like the introductory part of a longer article. The "why" is that if we assume,

This was a bit disappointing article by Quanta standards, pretty much just felt like the introductory part of a longer article. The "why" is that if we assume, as a thought experiment, that we have a magic black box that always gives the correct answer to some question that we otherwise don't (or can't) know the answer to, it can help us come up with and prove results about computational complexity that apply to the "real", oracle-less world too.