What is the idea behind 10.h3 in the Scotch Four Knights Kramnik introduced this idea in a couple of his games against Aroninan, but I am struggling to justify such a slow move in a rather open position:

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1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Nf6 5. Nc3 Bb4 6. Nxc6 bxc6 7. Bd3 d5 8. exd5 cxd5 9. O-O O-O 10. h3


Is there any other idea besides preparing Qf3 and avoiding Bg4?
Bg4 could be annoying to meet in this position for a few reasons:


It would force white to move the queen to an awkward square, play f3 opening the g1-a7 diagonal or play the passive Ne2.
White would prefer not to trade light squared bishops (with Be2) here as Bc8 is black's worse piece.
Ne2, Qd2 and f3 all allow Bh5 with the idea of Bg6 essentially forcing a trade of black's bad bishop