Oculus Quest in particular is in majority a non-steam headset. If you want to use it with steam, you need to buy an additional cable (Oculus Link).

When I see people talking about Oculus dominination technology-wise, they mostly talk about the Oculus Quest. More specifically, a wireless standalone headset that doesn't require static captors to have 6 degrees of freedom.

Someone correct me if I'm wrong, as I only started looking into VR recently.