Its the part that you omitted from your summary that makes the statement nontrivial—the idea that the metric theory (poetically, the warping of space) is only v

Its the part that you omitted from your summary that makes the statement nontrivial—the idea that the metric theory (poetically, the warping of space) is only valid as a low energy effective description, and the general case does not have a classical interpretation even in a limit. To put it another way: the quantum theories that are best understood are the ones that are similar to a classical field theory, but that’s not the case here.