Gravenberch is a decent player with a high ceiling.
Having Klopp, and having Gakpo+VVD at the club, might help him realise some of this undoubted potential.
As much as I love the class of Macca, Almiron kind of showed he does lack a bit of athleticism (though his mindset/intensity is outstanding).
RG doesn't lack athleticism, but he seems to swan around and although the stats says he covers a lot of ground, it's usually done at a leisurely pace. He seems to lack the intensity/mindset of a Macca (or typical Klopp-type player).
If Jurgen is able to get him to intelligently press (with intensity) and tackle (when he gets there), he'll be quite some player.