&gt; Is this where the translation from GR -&gt; QM breaks down?<p>Sort of, to get a graviton you introduce perturbations on a background metric. (Basically small wiggles of spacetime around an &#x27;average.&#x27;) You don&#x27;t do anything like that when you solve the Einstein equations. Consequently, the background spacetime ( that is, the black hole) is not really made of gravitons. (At least in some sense.)