Why not?
The energy of a 10 KM fall isn't that high because of terminal velocity. Like it's an impressive feat in the context of One Piece, but like preskip M3 have demonstrated more destructive attacks.
Boundman's Kong Gun to Doflamingo is >>>> 10 KM fall in energy.
It didn't look that destructive, but hurting Kaido while Boundman couldn't implies that it packed that much more force.