Synergy
Maybe saying that it was spacetime didn't really do it justice. Instead, it was more accurate to say that they had all been influenced by his Cosmos Fog, giving them just that added bit of power and Control.
With his Cosmos Fog attached to the foundation of these abilities, Ryu got the best of both worlds. On the one hand, his Dao Bones allowed him to communicate with the Heavens in a way a Human shouldn't be able to, but on the other, it also allowed him to exhibit Control that a beast wouldn't.
It could be said that though the Dragon Emperor was the first existence to show Ryu the sort of power that Control could exhibit, Control was actually a weakness of the beasts. That was because Control relied on influencing the world around you with your own will rather than allowing the Heavens to carry you instead.